# MK4 VR6 MAF sensor + Audi A8 MAF housing ???



## CorvetteKillerVr6 (May 9, 2007)

Im Running the Unitronic 440cc file but ive been using a custom made maf housing, very much like the 95mm I.D housing sold by C2 motorsports.
HOWEVER, the car kind of still runs like **** 
Unitronic recommends i be using an Audi A8 housing with my mk4 VR MAF sensor in it.

so here's the deal
im sick of these refurbished MAF sensors pouching, so where is the best place to buy a real OEM BRAND NEW one.???
i see ECS tuning has lots of them, but which one is best??
And Also, where can i source JUST a A8 housing by itself with out the sensor???(ill be trying The Source Vw in T.o tomrrow to see if they have anything)
any help would be great


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

anyone??

what is it with these MAF sensors dying so often??
yet nothing seems to really be wrong with it.....


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

what makes you think the sensors are dying?


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## lucas13dourado (Oct 1, 2007)

*FV-QR*

the dealer?


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## JVK (Dec 20, 2009)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_Im Running the Unitronic 440cc file but ive been using a custom made maf housing, very much like the 95mm I.D housing sold by C2 motorsports.
HOWEVER, the car kind of still runs like **** 
Unitronic recommends i be using an Audi A8 housing with my mk4 VR MAF sensor in it.

so here's the deal
im sick of these refurbished MAF sensors pouching, so where is the best place to buy a real OEM BRAND NEW one.???
i see ECS tuning has lots of them, but which one is best??
And Also, where can i source JUST a A8 housing by itself with out the sensor???(ill be trying The Source Vw in T.o tomrrow to see if they have anything)
any help would be great

Could you send me a picture of the wiring plug for your maf sensor? Then i will be able to support you with the original VW/Audi spare part number. The price is very low on a brand new one. But there a two different type's (on old type, same maf like a Mk3 VR6 / or new type like a VW Golf 4 1.8T 2000<)
You are also welcome to e-mail me with the picture [email protected]
Best regards from
Jacob


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (lucas13dourado)*

no,the EPC lights telling me the MAF readings are too low.
and all this is after replacing it and it worked for over 3 months.
now im getting TPS and other throttle body codes, and the car wont even idle.

BUT if i unplug the MAF, car idles and runs fine. AND the T/B codes go away!!!
WTF??
except it runs lean cause its in Limp mode


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## TBT-Syncro (Apr 28, 2001)

*Re: FV-QR (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_no,the EPC lights telling me the MAF readings are too low.
and all this is after replacing it and it worked for over 3 months.
now im getting TPS and other throttle body codes, and the car wont even idle.

BUT if i unplug the MAF, car idles and runs fine. AND the T/B codes go away!!!
WTF??
except it runs lean cause its in Limp mode
















i suspect that your ecu voltage is too low, and the maf is fine.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (TBT-Syncro)*

that could be.
i have the battery relocated to my trunk.
but i seem to be getting a constant 14v most of the time.
so i havent paid much attention to voltage supply possibly being an issue.

im running a 95mm C2 style MAF housing with the Unitronic 440 file, BUT Unitronic tunes there file with the Audi A8 housing.
so im still hunting for this Audi housing to see if that helps.
for the record, the car has been running seemy ok for the past 3 months of summer on the Juan made 95mm MAF housing.
but its had the odd putting and misfire caused by the housing being a little bigger.
but it ran ok.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (JVK)*

and yes, i can supply and picture of the end.
but im already sure that i MUST use the Stock VR6 MAF sensor in the stock audi A8 housing.
i just dont want to buy the whole MAF sensor/housing setup when I only need the A8 housing


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## JVK (Dec 20, 2009)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_and yes, i can supply and picture of the end.
but im already sure that i MUST use the Stock VR6 MAF sensor in the stock audi A8 housing.
i just dont want to buy the whole MAF sensor/housing setup when I only need the A8 housing

Hi again
Is it this type of sensor you use?


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (JVK)*

no its not that one.
thats from the MK3 vr

i have the newer mk4 style/
this is the MAF sensor im running in a homebrew housing just like the C2 motorsports style


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

like this one
http://www.mjmautohaus.com/cat...d=891


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

and its a 5 pin harness connector


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## JVK (Dec 20, 2009)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_like this one
http://www.mjmautohaus.com/cat...d=891

Okay you will get instant message on part number right away


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (JVK)*

the part # for which part?
i know i need the a8 housing for sure. but i think my MAF sensor might still be ok, i just bought it like 2000kms ago
but are you saying i could have a faulty harness connector that i should replace???


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## JVK (Dec 20, 2009)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_the part # for which part?
i know i need the a8 housing for sure. but i think my MAF sensor might still be ok, i just bought it like 2000kms ago
but are you saying i could have a faulty harness connector that i should replace???

For a couple of month ago all maf sensor prices made a drop from VW here in Denmark. I think it is the same in the US.
It would be more cheap for you to buy a complete A8 housing with sensor, instead of buying a used housing without sensor.
I cant say anything about the fault, sounds quite strange








But i have used this A8 maf on a lot of turbocharged VR6, 24V and R32 works perfect


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

so thanks to JVK, ive realised that a stock Audi A8 Sensor is the same one as a stock mk4 vr sensor, but the housing on the audi V8 maf is bigger.
so
i will be ordering the entire new stock A8 MAF to see if that cures everything and hopefully gets this cat running properly on 20lbs








so with that figured out, my last question is why was i getting all sorts of throttle body angle sensor codes?? and a throttle position sensor code as well.
but once i unplug the maf it goes away....
is it cause unplugging the maf puts the car into limp mode? which might also make it ignore the angle sensors in the T/B?? or could it somehow actualy be related to the MAF being bad?


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Awesome JVK, youve helped alot.
im ordering one right now and we'll see if that helps








thanx man! http://****************.com/smile/emthup.gif


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## JVK (Dec 20, 2009)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_Awesome JVK, youve helped alot.
im ordering one right now and we'll see if that helps








thanx man! http://****************.com/smile/emthup.gif









You are Welcome








I hope it will fix your problem








Best regards from
Jacob


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (JVK)*

JVK, i just installed the new sensor, AND housing and the EPC light did go away,and it did seem to make the throttle feel alot better, but it kept stalling.
BUT i do remember Unitronic trying to adjust some settings in the ECU for the MAF housing i had.

so maybe i need to find out what he changed in VAG-COM and change it back.

if he changed the MAF calculation by just a bit to conpensate for the bigger maf housing i had, would it make it stall now that ive installed the A8 housing and sensor they originaly call for for the 440cc tune???


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

and for the record, i am using the A8 SENSOR and the HOUSING.


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

spend the $200, buy a wideband setup, and figuring all of this out will be simple.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

im running the innovate lc-1 wideband.
the MAF causing the ECU to freak out i think is the issue


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_im running the innovate lc-1 wideband.
the MAF causing the ECU to freak out i think is the issue

whats your MAF reading at idle?
whats your 02 reading at idle?
whats your air/fuel at idle?
whats your timing at idle?
whats your TPS at idle?


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

ok,i will check all of these with vagcom tomorrow.
thanx man


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Im pretty new to Vagcom, i know group 060 is maf..
anyone help me out finding which blocks in Vagcom are for the MAF,the TPS, the O2, and timing????
so i can finally figure this out.


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## FaelinGL (Nov 28, 2004)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Short and long term trims (add / multi) are block 032. 
I'm surprised your car runs with the MAF unplugged. Soon as I unplug mine, the car dies. It may be the C2 software is very sensitive to MAF problems.
Mike


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## IHookItUuup (Aug 6, 2008)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (FaelinGL)*

I don't think he is running C2 fueling - maybe he should!? In VAG-COM as you click on the different measuring blocks text will pop up that tell you what feature you are measuring - just click until you find the feature you would like to measure ie. MAF, Coolant, Timing etc. Hope this helps.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (IHookItUuup)*

awesome man, yeah i finally just realised that if u hold the mouse the paerticular block it says what it is....
haha








i am running Unitronic 440cc tune .


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

what do i do about the idle issue??
it doesnt want to stay running.

how do i adjust the low idle?


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## FaelinGL (Nov 28, 2004)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_what do i do about the idle issue??
it doesnt want to stay running.
how do i adjust the low idle?

You will be able to adjust the idle using Vag-Com to a certain point. I wanted my idle higher, so I needed to use Lemmiwinks.
Mike


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## IHookItUuup (Aug 6, 2008)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (FaelinGL)*

FaelinGL is correct. Download Lemmiwinks if you want to want to adjust idle speed and startup enrichment. GL and keep us posted so that we know what works.


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (IHookItUuup)*


_Quote, originally posted by *IHookItUuup* »_FaelinGL is correct. Download Lemmiwinks if you want to want to adjust idle speed and startup enrichment. GL and keep us posted so that we know what works.

you can raise/lower the idle with vag-com. not sure about on the mk4, but on the mk3 its > adpatation >channel 01, (128 is default value).


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## FaelinGL (Nov 28, 2004)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*


_Quote, originally posted by *TBT-Syncro* »_
you can raise/lower the idle with vag-com. not sure about on the mk4, but on the mk3 its > adpatation >channel 01, (128 is default value). 

This is correct, but I've found with the C2 software, I can only get channel 1 up to about 132 (which I think is like 650 rpm). I need mine around 750-800 to get rid of the vibrations from the VF Mounts, so I had to use Lemmiwinks. It may be different for your software however.
Mike


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (FaelinGL)*


_Quote, originally posted by *FaelinGL* »_
This is correct, but I've found with the C2 software, I can only get channel 1 up to about 132 (which I think is like 650 rpm). I need mine around 750-800 to get rid of the vibrations from the VF Mounts, so I had to use Lemmiwinks. It may be different for your software however.
Mike

thats strange. with the mk3 software, each unit is equal to 8rpm. So on a mk3, having it set to 132 would mean an idle speed of 1050.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

hmmmmm so after a whole day of getting my computer and vag-com going.
i also got lemmiwinks going finally.
the car runs great if i manualy keep it idling, but if i let the gas go it will slowly slowly die out to a complete stall.
other then that, the throttle response is way better with the Audi MAF housing and sensor. AND i also noticed i dont get the EPC light or any throttle body codes, nor do i get any of the anoying backfiring i was getting before.
seems to runs fine now just wont idle, it will stall right out.
so here's the thing, and this might help u guys find me an anwser.
before shutting it down for the night i decided to toy with my adjustable fpr and when i pulled the vacuum line off it. it seemed to go right back to idling fine!!









so why would it do this when i create a vacuum leak?? does a vacuum leak not lean out the car by adding more air??????


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*


_Quote, originally posted by *TBT-Syncro* »_
whats your MAF reading at idle?
whats your 02 reading at idle?
whats your air/fuel at idle?
whats your timing at idle?
whats your TPS at idle?










So to i can't even give u guys these values cause it wont idle without a bit of foot on the gas.....


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

i also made a boost pressure testing unit from homedepot parts and will be testing for overall boost/vacuum leaks tomorrow..
i quickly tried it the other day but didnt have much time, but i did notice my DV wouldnt even hold 15psi.... even with it cranked and its a 7-17psi DV but i could hear it slowly leaking out








i just dont under stand why a leak would HELP it idle and not make it ****ty..
anyone??

for the record, my DV has its vacuum POST t/b and my wastegate is just pre-t/b.




_Modified by CorvetteKillerVr6 at 10:55 PM 1-16-2010_


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_
before shutting it down for the night i decided to toy with my adjustable fpr and when i pulled the vacuum line off it. it seemed to go right back to idling fine!!










sounds like fuel pressure is possibly too low. by removing the vac line, you added about 5psi of fuel pressure.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

yeah im guessing either fuel pressure or vac leak.
i am going to double check to make sure the walbro inline pump is healthy and then see where im at.

with the vac line OFF the fpr, im just under 60psi, say 58psi with it idling.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

im really going to check the walbro pump good, come to think of it, i coudlnt really hear it earlier.
i remembered it making quite a wine when it was running......
maybe im not getting enough fuel flow...
yet i some how have lots of the usual pressure
60psi give or take


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_yeah im guessing either fuel pressure or vac leak.
i am going to double check to make sure the walbro inline pump is healthy and then see where im at.

with the vac line OFF the fpr, im just under 60psi, say 58psi with it idling.


is a mk4 supposed to be that high? or is it that Uni tunes it for higher fuel pressure. with a mk3 we are 38psi.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

yes, Unitronic is a 4 bar tune.
so what do u think i should do?
im guessing its not enough fuel, or its a vac leak.....
what are ur thoughts?


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_yes, Unitronic is a 4 bar tune.
so what do u think i should do?
im guessing its not enough fuel, or its a vac leak.....
what are ur thoughts?

if you can, drop the fuel pressure down to 50psi (with the line connected), and see what happens.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

ok, so your thinking its running rich,??
ill check the pump and if its working ill drop the pressure down and see what happens.
hopefully something good comes of it


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Wow, no luck at all with this allll day!
im am getting pretty bummed out now.
i tried lowering the fuel pressure, and also raising the idle with lemmiwinks, and it still will not keep the car running. The Walbro pump is fully functional and working fine.
I checked the entire setup for vacuum leaks, and found nothing. I even went as far today as to bypass the intercooler, then i bypassed the entire turbo setup and put the maf right onto my t/b and it STILL runs like **** and wont idle and dies in the same exact way every time. it just slowly slowly dies out to nothing.
I also tried using vag-com to reset back to the factory defaults of the Uni 440cc tune using the 01 group, and nothing. 
I know Michel at Unitronic had adjusted something when i went there, and had the 95mm C2 style housing Juan8595 made me with my stock vr6 sensor. they noticed it wasnt the A8 housing and told me that was probably my problem, but in the mean time he figured he would adjust something to get rid of the EPC light i was getting, and it did work for a bit, i made it home from montreal but then it came back again.
i think he said it was fuel maybe down low, then another setting for the fuel up higher???









either way im so lost........ and maybe regreting not going with C2 tune...........?







that way the housing i had would of worked just fine.....


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

he said it was something that is adjusted in the ECU to make it think it was actualy a smaller MAF than the 95mm i had...

but ive used, Unisetting 1.4, Lemmiwinks, and also VAG-COM to default all of this stuff..
so should i not be right back to the stock Uni440cc file???

or do they have there own software he could of used to change something in there coding that i cannot change via vag-com or lemmiwinks/Unisettings 1.4??

this is the MAF im running ( using both the housing and the A8 sensor). and with my foot on the gas, it does run way better than before, it just wont idle!!


_Modified by CorvetteKillerVr6 at 5:17 PM 1-17-2010_


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## IHookItUuup (Aug 6, 2008)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

When you unplug the MAF does it idle? If so - switch back to the MAF & MAF housing that the tune was adjusted for. The ECU does not know how much air the engine is getting. Post a pic of your setup so that anyone viewing your post can help. Is you DV recirculated?


_Modified by IHookItUuup at 7:58 AM 1-18-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (IHookItUuup)*

see thats the thing, he never really got it perfect with the c2 style housing and my vr6 sensors, it does seem to run way better on this A8 one but it dies out.








and when i unplug the maf it will idle,but will after a longer period die eventualy.

ill post some pics up in a bit


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

and also, that was my question...
is there something unitronic could of changed in the actualy coding of there tune to adjust for the maf size or is this something they would of done via vag-com???
cause i did a default reset with vag-com and it didnt help.
so what ever he did is in the actual uni440cc tune on my ecu


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Soo,I spoke with Michel @ Uni today, turns out he says he actualy changed the MAF calculations in the Unitronic file/coding.
In which cannot be changed via Vag-Com/Lemmiwinks/Unisettings...........








he says they will re-flash my ECU with the original 440cc tune they gave me for free.
but looks like im out 60$ shipping sending it there and back.

but they seem to be pretty confident that now with the A8 maf i should be fine once the tune is back to the original 440cc.

wish me luck


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

So today i figured it out.
Michal told me to try the A8 sensor in the custom MAF housing Juan made me, that Michal had attempted to tune it too back when i paid them a very quick visit before Vagkraft 09.

so today i tried that combo and the idle issues went way.
it idles no problem again and i got some logs in vag-com.
at Idle im getting:
700rpm 
Maf: 9.00-9.53 g/s 
Ign Timing: 15-17 degrees BTDC with the odd weird blip down to 5 or 6.
O2 : group 006 said:Lambda -3.1%
group 001 said: Lambda 26.6%
TPS is around 3.5% load
and Air/Fuel is just under 12 at idle.


_Modified by CorvetteKillerVr6 at 6:17 PM 1-19-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

WTF!!!
i just got the ECU back, the apparently re-flahsed me for the original 440cc tune using the A8 maf housing.....
now the car wont even run, a8 maf housing with the a8 sensor OR my stock sensor!
im really fed up with this


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_WTF!!!
i just got the ECU back, the apparently re-flahsed me for the original 440cc tune using the A8 maf housing.....
now the car wont even run, a8 maf housing with the a8 sensor OR my stock sensor!
im really fed up with this

did you re-adapt the throttle body after you plugged it in?


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

duddesss..... i cannot ****ing believe it.
they sent it back to me re-flashed with the 630cc tune!!!!








WTF?

someones totally dropping the ball here man.
i sent them an entire letter of my specs and what i wanted.....
yet they still screwed up
before it read in Vag-com (UNI/440c ME7.1)

NOW it says (UNI/630c ME7.1)!!
and i dont even have these injectors


_Modified by CorvetteKillerVr6 at 11:56 AM 1-28-2010_


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## IHookItUuup (Aug 6, 2008)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Thats probably a better tune! Keep it and upgrade the injectors and you are good to go! Be sure the MAF and housing is correct for that tune. With the 630 tune you can increase the boost later if you like.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (IHookItUuup)*

but im still on stock block, 8.5:1 of course but i just want the 440 setup. i liked it, i just wanted whatever he messed with in the MAF section changed back to its original 440cc state.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Either way, they've realised the mistake and picked it up via Fedex this morning and promised to have it back to me for Saturday delivery.
atleast they suppost there ****


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

Turns out, i had the wrong Audi A8 maf housing......, the whole time!!
077133471GX instead of 077133471JX!!!

I cant believe i screwed up by one letter in the part # when i ordered it.....
hopefully now im set, the tune is back to the Proper Unitronic 440cc tune.
and the proper maf is on the way... http://****************.com/smile/emthup.gif








Ben @ ECS tuning was cool enough to let me return the one that i got that wasnt the right part# in exchange for the one i need.
i order alot of stuff from these guys and there one of the best Tuning stores out there
ECStuning.com

thanks man!


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

So now i need some help.....

i've got the right housing Unitronic recommends for the 440cc tune, but now, the 2 different AFP vr6 sensors i have still give me the EPC light, So i think there both pouched.....

i really need a mk4 vr6 sensor to try this out with......
anyone have one that they are POSITIVE works just fine.>??????
i am willing to pay a small amount via pay-pal for someones old 2001 VR6 maf sensor.

The housing they recommend... Part# 077133471J 
-With the 2 VR6 sensors i have, i get the EPC but the code says "MAF SIGNAL TOO LOW"
-With the Audi A8 sensor out of the 077133471J i bought , it reads "MAF SIGNAL TOO HIGH"
and if i put just a tiny square onto the middle of the maf air straightener using the Audi housing AND the audi sensor.... im able to get the light to go away entirely........ but only at idle...

it idled with no EPC for the first time, but only till i got it out to the street..... then the light came back
Steve @ Unitronic, is convinced its not the housing or there tune..
And im positive its not my wiring.
heres a few pics of how its setup...








AND here's the combo i used that got rid of the EPC but only at idle....
AUDI Part# 077133471J with the Audi sensor thsat came with it...


Please help guys!



_Modified by CorvetteKillerVr6 at 11:15 AM 2-15-2010_


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## TBT-Syncro (Apr 28, 2001)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

you're wasting time until you verify that its not the wiring.
put a voltmeter on each line at the maf pins, and the other side at the harness, and verify there is no resistance.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*

that was my project for today!!








u read my mind, i was actualy just checking up the MAF pins on the ECU side of the harness to see where to locate them to check.

so i should be looking for no resistance at all??
0 ohms on my voltmeter?
Thanks in advance TBT


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (TBT-Syncro)*


_Quote, originally posted by *TBT-Syncro* »_you're wasting time until you verify that its not the wiring.
put a voltmeter on each line at the maf pins, and the other side at the harness, and verify there is no resistance.

So if there is any resistance in ohms at all. then what?
could it be the connector at the maf end??
everything is soldered properly and shielded.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

i can't seem to find the MAF wiring pins on the ECU end....
anyone??
i need to know which pins on the ECU end match up with the MAF harness end.
.....










_Modified by CorvetteKillerVr6 at 5:58 PM 2-15-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

K found it.
so here's the resistance readings, in ohms. all of these readings were taken using a Fluke voltmeter, with a paper click soldered to the end of one tip to get into each pin of the ECU end of the harness.
for this Maf connector.
http://farm4.static.flickr.com...2.jpg
with the pins the way they are in this picture.
the first one on the left read: 0.6ohms
second from the left read :0.6ohms
third from the left read:0.5-0.6ohms
fourth from left read(ground):2.8ohms.(this varied alot depending on the ground point i selected, in this case i was able to get the lowest impedance by touching the actual ECU's Metal casing)
fifth from the left read:0.6ohms
the connector terminals seems very clean, aside from the little bit of busted plastic the terminals/ and connector seem to be ok.








ill wait till i can try a 100% brand new working sensor i guess


_Modified by CorvetteKillerVr6 at 7:52 PM 2-15-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

anyone else gone through this?


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## lucas13dourado (Oct 1, 2007)

*FV-QR*

I didnt read the whole thread.. but are you sure you are supposed to use the MAF housing only?
maybe you need the whole MAF + sensor?
Im running Eurodyne and they switched to the audi 4.2l maf.. sensor and everything
just an idea :bee:


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (lucas13dourado)*

yeah Ive gone over that with them a few times to make sure.
Unitronic 440cc tune uses the 01 Audi A8 (AUX)housing + the stock 2001 VR6 sensor.
its weird why all these companies chose to tune to different maf sensor/housing combo's








im waiting to hear back from Jacob @ Unitronic this afternoon.
he is trying to source me a couple stock VR Sensors to send my way.
and im also going to change the connector just for ****s


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (lucas13dourado)*


_Quote, originally posted by *lucas13dourado* »_I didnt read the whole thread.. but are you sure you are supposed to use the MAF housing only?
maybe you need the whole MAF + sensor?
Im running Eurodyne and they switched to the audi 4.2l maf.. sensor and everything
just an idea :bee:

and plus ive tried the Audi sensor aswell, and instead of MAF signal to low, it gives me MAF signal too high with the Audi one..


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## Mr Boosted (Mar 10, 2009)

*Re: FV-QR (CorvetteKillerVr6)*

C2 MOTORSPORTS http://****************.com/smile/emthup.gif


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (Mr Boosted)*

would u like me to post the 5 threads ive found of poeple having big issues with the C2 440cc software?????

its just as bad trust me. http://****************.com/smile/emthup.gif


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

im still getting the EPC light with this tune.
ive got the right housing, and the right sensor but am still getting MAF signal too low or to high.

there is no resistance in my maf wiring or my Throttle body wiring......


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## TBT-Syncro (Apr 28, 2001)

*Re: FV-QR (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_would u like me to post the 5 threads ive found of poeple having big issues with the C2 440cc software?????

its just as bad trust me. http://****************.com/smile/emthup.gif









but was the problem the software, or something in the hardware.....


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## TBT-Syncro (Apr 28, 2001)

*Re: FV-QR (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_im still getting the EPC light with this tune.
ive got the right housing, and the right sensor but am still getting MAF signal too low or to high.

there is no resistance in my maf wiring or my Throttle body wiring......











put in a stock ecu, stock sensor, and stock intake, and see if you still get the code.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (TBT-Syncro)*


_Quote, originally posted by *TBT-Syncro* »_
put in a stock ecu, stock sensor, and stock intake, and see if you still get the code.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

But the car ran OK on the same tune that they had "modified" for the C2 style 95mm housing and stock sensor......








i would still get the EPC light but only every now and then, then it would go away and go back to full power again.
after 6 months of driving like that, i decided enough was enough and wanted the tune 100% perfectly tuned with the exact MAF and sensor they call for.....
so i bought the right MAF housing and sensor, AND had Unitronic RE-flash my ECU with the original 440cc tune they had shipped me to begin with, before everything got played with At there headquarters in Laval.

now that i have the so called "proper" MAF housing (01 Audi A8 4.2 Maf housing) + my stock 2001 VR6 sensor, the car is ALWAYS going to EPC mode, 
Same intake, same filter, same turbo, same everything.
except the ECU tune and the MAF HOUSING.....


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

it turns out, some of this could possibly be cause cause i deleted the SAI and PCV...

im getting the codes from these things, causing the ECU to not adapt, and playing with fuel trims.
so i am on my way to hunt for resistors to work this **** out.

im sick of it


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## matchew (Apr 11, 2006)

*Re: FV-QR (CorvetteKillerVr6)*


_Quote, originally posted by *CorvetteKillerVr6* »_it turns out, some of this could possibly be cause cause i deleted the SAI and PCV...

Just get Uni to turn them off!


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (matchew)*


_Quote, originally posted by *matchew* »_
Just get Uni to turn them off!

They can't on mk4's yet!
so it needs to stay in.
even C2 cannot fix the improper SAI flow code, so the car wont pass Canadian e-test.

in the mean time, ive found some 330ohm,5w,5% resistors to use for the SAI pump, the SAI Solenoid, and the Intake changeover Solenoid.








i should mention that im still getting the MAF signal too low, EPC light.
even with these resistors installed ( without the Solenoids, just the resistor ends stuck into the 2-pin harness connectors, of all three.
i still get codes, the only one that goes away is the Intake change over Solenoid code..... 

here's what im getting when i scan with Vag-Com.(weird part is the EVAP codes, as all my evap is still plugged in with the purge valve and check valve under the hood. as for the leak detection pump, it could be shot?

17833-Evap Purge Valve(N80):short to ground 
P1425-35-00
17880-Evap leak detection Pump: short to ground
P1472-35-00
17843-Secondary air injection pump relay(J299): short to ground
P1435-35-00
17840-Secondary Air injection Solenoid Valve(n112): open circuit
P1432-35-00
17525-O2 sensor heating circuit :B1 s2:short to ground
16486-mass air flow(g70):signal too low




_Modified by CorvetteKillerVr6 at 4:46 PM 2-28-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

am i wiring the resistors in to the harness the right way, like one each end of the resistor into the 2 pins of the harness??
or does it requrie the solenoid to be plugged in and the resistor installed inline with the wiring aswell?


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

i really dont get why im getting evap codes...
the purge valve is still there and plugged in and still have the lines to it,
and ive never ever touched the Evap detection pump in the rear passenger wheel well....


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

So still trying to hunt for this short to ground...
last night i found out that two wires of the maf should be ground.
and two in the T/B connector should be grounds.........
i found all of this out by using my fluke meter on a friends 2001 vr6 that sis completely stock.
and his had two grounds in the maf connector. the big blue/yellow one and the little green wire.
and the throttle body also had two ground, which mine only has one.......

it seems the ground splice in my stock harness wiring in the rain tray is messed or something in my wiring under the dash maybe.
like my turbo timer install or the turbo timer CCM wiring circuit i used to make the doors lock while the turbo timer is still running.
has anyone ever saw random short to ground codes like this???
ive ripped out and checked almost all the wiring........
and to see if it was a relay, i pulled 409, 100, and others etc. and it didnt make a difference.
i still get these two EVAP short to ground codes, and a MAF signal to low.
but these could all possibly be ground issues........

i dont know what else to look for.









i really really wish i had a wiring pro here to help me trouble shoot this in my shop....
_Modified by CorvetteKillerVr6 at 11:13 AM 3-7-2010_


_Modified by CorvetteKillerVr6 at 11:15 AM 3-7-2010_


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

So ive finally found the wiring issue i had cause all the short to grounds.
i had a cut front o2 wire and a MAF wiring issue as well.
so now, with all the resistors in place, the EVAP and SAI codes are gone, and my rear o2 is re-installed so that code is gone too.
but the one and single code i get now is MAF signal too low still.....









my intake seem to be 100% leak free, and ivew even tried a peice of pipe infront of the maf to help it out, and still, maf signal is off


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## .LSinLV. (Nov 13, 2009)

*Re: FV-QR (CorvetteKillerVr6)*

http://****************.com/smile/emthup.gif good to hear.
why not just rewire the MAF from the factory location (or futher back) and use a new plug/pins at the MAF???


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (.LSinLV.)*

it is just an extension onto the stock wiring, a small extension, maybe 16".

i have a new maf connector on order to eliminate that possibility


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## CorvetteKillerVr6 (May 9, 2007)

*Re: FV-QR (CorvetteKillerVr6)*

i dont know if that maf needs more pipe infront of or behind it, or if the DV re-circ is too close to the maf..


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## CorvetteKillerVr6 (May 9, 2007)

*Re: MK4 VR6 MAF sensor + Audi A8 MAF housing ??? (CorvetteKillerVr6)*

These pics are a bit old, the sensors in the pics are not the ones being used, neither is the housing.
_Quote, originally posted by *CorvetteKillerVr6* »_
pics of the setup






AUDI Part# 077133471J with the brand new 2001 vr6 sensor...

Please help guys!
_Modified by CorvetteKillerVr6 at 11:15 AM 2-15-2010_


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## IHookItUuup (Aug 6, 2008)

I am battling the dreaded "Evap Purge Valve - short to ground" CEL as well. I haven't found any way to shut it off and my system is intact as well - I noticed that after I clear the error and start the car the light may not come on for several minutes after I start driving - so I am thinking that in my case it is a software issue.


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## CorvetteKillerVr6 (May 9, 2007)

*Re: (IHookItUuup)*

So im at the end of the line...
asking for my money back from Unitronic today..
Jeff @ C2 has given me the ok that his 12v 440cc tune will not give me any EPC or MAF codes with the other C2 housing i have....
and there tune deletes the SAI...
so id be all set, so i asked for a refund today.. so we'll see how that goes..
i better get my $$ back, tell u that much.
ive been dragged along for over 8 months now, constantly being told my setup isnt right, and that my maf is bad, and the housings wrong.....
and in the end, it's there tune, that cost me $900 Canadian + all the MAF housings and sensors ivew had to buy (well over $300 Canadian).
so over 1200$ im out, and the turbo tune still isnt right.


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## boser18t (Apr 16, 2006)

i would love to hear an update on your vrt adventures. im somewhat in the same boat. i do not have any codes except for the rear o2. i have unitronics 630cc file and i am about to buy the correct audi maf housing. i did the resistor mod as i also deleted sai. i did keep the evap purge valve plugged in. going to lengthen the intake pipe before the maf. i used 330 ohm resistors but they were 10 watt not 5.. i read a writeup from a guy who did it using 10 watts and he was cel free for 10k miles at the time he did the writeup. my car runs decent with the homemade maf housing i made from home depot using pvc pipe the same inside diameter as the audi maf. the difference, which i think is causing all my problems is theres no mesh in the maf housing i made that straightens the air out for a good reading. so my air fuels are always unstable.


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