# 2007 Rabbit, LNT intake, failing emissions due to leaks



## berfles (Oct 29, 2011)

I tried to get my Rabbit inspected and it failed emissions. It's had a CEL for awhile and was complaining about the MAF and throttle correlation. I took it to the VW dealership and after running it through a smoke test they found that the breather tube that runs under the intake manifold had two holes in it from rubbing against a wiring harness or something, probably due to this LNT intake that was on the car when I bought it. I told them to replace the tube since it was only another $200, and after they did that they found another leak where the intake actually connects to the manifold. I need a new tube and a new air filter basically. I may have the stock parts that I can throw on to get it past emission tests, but where should I look for a new connecting pipe? I also have no clue what filter to get because none of the local filters fit the configuration, the one on there is a K&N tapered oval filter but I don't have any measurements right now.

I guess long story short, what's the best place to get a new intake connecting tube and a new filter?


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## le0n (Jun 12, 2013)

200 for a hose? does not compute.

also, take photographs of what you are asking to replace.

do you still have the LNT installed?


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## berfles (Oct 29, 2011)

The $200 included labor, I needed it done quick because it's out of inspection and since they already charged $400 for the labor/diagnostics the first time I didn't care about another $200.

The LNT is still on the car. Here is a picture of it as it stands right now:










The notes from the tech say that the intake is leaking at the clamps, I'm assuming where it connects to the throttle body. I was thinking of just saying screw it and buying a Carbonio intake, then I don't have to worry about finding a filter that fits in the crammed space with this LNT because there is barely any room where the intake itself ends. Although then again, I don't know what other types of filters will work best with this setup, suggestions on filters? Or should I just buy the damn Carbonio?


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## berfles (Oct 29, 2011)

LNT intake off, stock intake back on. 










I have a pending "System Too Rich" fault, don't know if the other stuff will come back. Car still hesitates under acceleration, which is what started all of this. I bought a new MAF a year ago thinking that was the problem but apparently either this one is **** also or it never was the issue. Still want to buy the Carbonio intake, but any ideas on what is causing the damn thing to stutter and hesitate under hard acceleration? 


Also, what the hell is missing from this space? I don't have any more stock parts and have no clue what was originally there.


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## gugu1981 (Jul 25, 2011)

berfles said:


> Also, what the hell is missing from this space? I don't have any more stock parts and have no clue what was originally there.


I don't believe anything is missing. That space is empty to begin with.


Peter


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## le0n (Jun 12, 2013)

yeah. vw left that empty for our cai intakes. they even made an extremely nice cut-out into the fender area.

edit: did your LNT have a custom maf insert or cookie cutter plate to correct air flow across the maf sensor? if not, it will most likely throw codes.


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## berfles (Oct 29, 2011)

le0n said:


> yeah. vw left that empty for our cai intakes. they even made an extremely nice cut-out into the fender area.
> 
> edit: did your LNT have a custom maf insert or cookie cutter plate to correct air flow across the maf sensor? if not, it will most likely throw codes.


I'll have to check it again, but it didn't seem cookie cutter. With the stock system back in place it's still dying on me. There's something bigger going on than just the MAF. Could it be an o2 sensor?


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## berfles (Oct 29, 2011)

Here is a log from Torque, looks like my O2 is bad.



> Mode $06 report generated by Torque for Android
> ================================================
> 
> Vehicle VIN: WVWAS71K87W200249
> ...



Here is also a summary I wrote to the best of my memory from the beginning:

First off, the car was bought with a Magnaflow exhaust and LNT cold air intake. Everything else is stock. About a year ago I noticed it would buck/hesitate/stutter under acceleration. Since everything seemed to point to the MAF, I ordered a new one and replaced it. The same thing kept happening. I was pulling codes for cylinder misfires so I replaced the coilpacks and fuel pump as well (I read a bad fuel pump could cause stuttering). Same thing kept happening. Since I got fed up, I just disconnected the MAF for awhile, which made it idle like ****, but eliminated any sort of hesitation/cutting out under heavy acceleration. When it got colder out I decided to try hooking the MAF back up and I ran the season with no issues. No hesitation. The CEL light was on for the duration though, and it either bitched about the MAF or throttle correlation.

Anyway, fast forward to a few weeks ago, I went to get it inspected and was told it failed emissions due to the CEL. I took it to VW to get it looked at and at first they said the car wasn't even seeing that the MAF was present. They hooked up a known good MAF and had the same result, so they wound up re-pinning the connector which apparently fixed that problem. Eventually they told me they ran a smoke test and found a vacuum leak in a breather tube that ran around the oil filter, and that because of the aftermarket CAI, it was rubbing a wiring harness and wore holes through the tube. At that point I was already $400 in because of the diagnostics, so I told them to just order the damn tube and install it for another $200. They had to special order the part so I told them to give me my car back because it was out of my hands for three days and I needed a car. After I got the car back, now with it being able to detect the MAF, it started shutting off on me while I was driving it. It's not entirely fun having a car lose all power at 75MPH on the highway. It did this numerous times, so once again I unplugged the MAF and it was better. I called VW again to let them know this, and they said that because of the strict fuel tolerances, the leak was probably throwing off the MAF and causing the headache. I said fine, brought the car back to them so they could replace the breather tube, and they called back saying there was ANOTHER leak where the CAI conencted to the throttle body. He told me it was still failing emissions, and that if I had the stock parts it would probably all be fine.

So on Saturday, I put the car back in stock configuration, hooked the MAF back up, and took it for a test drive. Right away it was hesitating and stuttering all over just like it always used to, and later that day it just started dying again. Now I'm pulling a P0172/System too rich code. I'm $600 into this ****, they made the car run even worse, it's still out of inspection and I'm driving it because I have no choice. I'm going to call them today and say just that, that I gave them $600 to fix it and all they did was make it shut off while I drive the thing.


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## le0n (Jun 12, 2013)

dude, you should have started off your thread with this info. i can't say that you'd have a solution by now, but at least those trying to help would have had all of this to throw ideas against.

hold off on swapping the Bank 1, Sensor 2 (*Rear O2 Sensor*). this sensor does not contribute to the Air/Fuel calculations. The Bank 1; Sensor 1 (Front O2 Sensor) handles this.

Keep in mind that if the Bank 1; Sensor 1 reads too much Oxygen, it means that there is a leak after the MAF; therefore, the ECU has no idea how to properly adjust the A/F ratio. It will continue to add fuel to compensate for the Lean condition; in turn, creating a Rich condition.

Also keep in mind that without the MAF being used for an entire season, the ECU again had no idea how to calculate with that missing variable, so it would have added fuel to prevent running Lean (running lean damages internal parts). This additional fuel over an extended period will essentially burn your catalytic converter. Hopefully that is not the case here, so we'll try to rule that out.

First things first, getting the engine to not shut off.

Please post the odbii error codes from Torque. Go to "Fault Codes" on the main Torque screen and post what it finds please.

Edit: please list the current mileage for the engine

Edit2: is your car PZEV?


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## berfles (Oct 29, 2011)

le0n said:


> dude, you should have started off your thread with this info. i can't say that you'd have a solution by now, but at least those trying to help would have had all of this to throw ideas against.
> 
> hold off on swapping the Bank 1, Sensor 2 (*Rear O2 Sensor*). this sensor does not contribute to the Air/Fuel calculations. The Bank 1; Sensor 1 (Front O2 Sensor) handles this.
> 
> ...


Yeah, I didn't have time when making the post to sit and rehash everything, I posted out of frustration. 

My VIN has a W in it, so non PZEV? Mileage is about 107k, and for the error codes should the MAF have been connected for awhile or disconnected?


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## berfles (Oct 29, 2011)

Ok, well at any rate, here are the codes it pulled from this morning with the MAF disconnected.


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## le0n (Jun 12, 2013)

cool. and what about the triggered codes with the maf plugged in?

not sure about the vin identification for pzev. you could do a free lookup here: http://www.vindecoder.net/

also, pzev rabbits came with non-clicking gas caps.


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## le0n (Jun 12, 2013)

P0101 - MAF related (Mass Air Flow Sensor (G70): Implausible Signal)
P0102 - MAF related (Mass Air Flow Sensor (MAF/G70): Signal too Low)
>> these are both maf codes that could result from the maf being disconnected
>> clear codes and test with maf connected for fresh error codes

P0113 - Intake Air Temp. Sensor (G42): Signal too High
>> i wonder if the IAI sensor wiring is ok?
>> perhaps testing for codes with this unplugged.

P0172 - Rich reading at o2 sensor - (could be from post maf leaks(vacuum leaks) or even a bad maf)
>> inspect for vacuum leaks. there are not too many places for them to develop on this engine. inspect each hose connecting to the intake/intake tubing. also inspect the plastic intake manifold itself for cracks.
>> in your case, there may be a large leak that can be easily detected by spraying a fine mist of throttle body cleaner over the engine bay while the engine is idling. if there is a vacuum leak (on a hose or gasket), your idle will change when the volatile vapors get sucked into the engine.

how is the idle? what rpm? is it relatively steady when the vehicle is just in park?


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## berfles (Oct 29, 2011)

How long do I have to drive for sensors to reset and give me new codes with the MAF plugged in? Because it's really not drivable that way, I can't even merge onto highways with how bad it hesitates under acceleration. I'll try your suggestions, but the IAT sensor was actually never plugged into the LNT intake, it was strapped to it. I only plugged it in after I put the stock setup back in place so maybe it is actually bad, I'll unplug it again.

I drove it today without the MAF and it's idling very rough, rougher than I remember it ever being last time I unplugged in.


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## le0n (Jun 12, 2013)

^^ you immediately clear the codes with Torque. plug the maf in, then let it idle in the driveway until the cel is triggered. if no cel triggers, just drive on your street a little bit or in a parking lot. based on your details, it should trigger relatively quickly.

then read the "fresh" codes.

edit: the maf should never be unplugged. i know your reasons for doing so, however, i'm surprised that the vehicle is allowed to even run extended periods of time without it present.


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## berfles (Oct 29, 2011)

Ok, I'll mess around a little after my workout.

As far as the PZEV stuff, my gas cap doesn't not click. The VIN decoder doesn't say anything about it being PZEV or non PZEV and I can't find anything in the engine bay either. If we're going by the gas cap thing, I guess it is PZEV. I'll post back later with the other info.


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## le0n (Jun 12, 2013)

berfles said:


> As far as the PZEV stuff, my gas cap doesn't not click. The VIN decoder doesn't say anything about it being PZEV or non PZEV and I can't find anything in the engine bay either. If we're going by the gas cap thing, I guess it is PZEV. I'll post back later with the other info.


well, the pzev rabbits have two catalytic converters & three o2 sensors, and i saw on your readout that Bank 1; Sensor 3 (last o2 sensor on second cat converter) had data.

i believe the federal warranty covers the rear o2 sensors and cat converters for up to 150k miles. so if something is diagnosed as faulty on any emission parts, check the federal warranty details before shelling out any cash.


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## berfles (Oct 29, 2011)

I'll keep that in mind, I had read something similar, thanks.

Just took it for a drive for about 20 miles, highway and back roads. Now for your questions:

The idle is very steady when it's just sitting there, around 780-840RPM. I unplugged the IAT sensor, plugged the MAF back in, and it didn't seem to start hesitating until it came up to temp. As I was driving in the beginning it didn't shut off on me, but toward the end it died 4-5 times. Never when I'm actually in gear so far, but if I come to a stop or coast in neutral it dies. CEL hasn't come back on yet, but there are two pending faults again:












Between the hesitating and it randomly dying it just isn't possible for me to drive it that way, so I'm going to have to unplug the MAF again. I could handle the hesitating but I will not risk the car shutting off when I'm doing 75 on the highway.


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## le0n (Jun 12, 2013)

P0068 - MAP/MAF <-> Throttle Position Correlation
>> where did you get the replacement MAF sensor from?
>> do you still have the old one for testing?
>> Did the dealership ever clean the throttle body and then perform a throttle body alignment?

read the details at ross-tech: http://wiki.ross-tech.com/wiki/index.php/16452/P0068/000104

P0172 - Rich reading at o2 sensor - (could be from post maf leaks(vacuum leaks) or even a bad maf)
per ross-tech: http://wiki.ross-tech.com/wiki/index.php/16556/P0172/000370


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## berfles (Oct 29, 2011)

I got it from AutoPartsWarehouse, I don't think it was OEM and probably should have been. I doubt I have the old one anymore, and as far as I know the dealership didn't clean the throttle body or perform the alignment, at least according to their notes.

I decided to drive the car to work today with the MAF connected to see what else it would pull. All sorts of fun things happened. First, an updated log while it was idling shows that the O2 heater monitor failed. Also note all the misfires.



> Mode $06 report generated by Torque for Android
> ================================================
> 
> Vehicle VIN: WVWAS71K87W200249
> ...



And here are the latest codes:


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## le0n (Jun 12, 2013)

man, it really does seem like the maf sensor has flaked.

if you can personally attest to their being no vacuum leaks, then i'd look to cleaning/testing the maf next. it is an extremely sensitive part, so follow a diy for cleaning.


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## le0n (Jun 12, 2013)

does Torque let you see the readings for the MAF sensor? it should. i only have a MAP sensor so I don't see the MAF PID data come up on mine.

it should show a calculated value for the volume of air passing over it. see what that value is at idle, then watch in real time (or log) what that value does when your rpms are raised.

log the maf, throttle position and rpms to look for the mis-correlation.


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## berfles (Oct 29, 2011)

Thanks for your help le0n. 

Long story short, it has been the MAF all along like I originally was thinking. I need to know who makes the OEM MAF for my car though, this site lists a few and the only one I think it may be is the Bosch. The dealer quoted me $212 for the new one, but I can't believe I can't find one cheaper myself and it's a 5 minute install.


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## le0n (Jun 12, 2013)

check ebay for the oem part. 212 is not a bad price though. you may be able to get a used part with a long warranty for less than 100 on ebay.

good luck.


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## berfles (Oct 29, 2011)

Just realized the stupid link I mentioned never pasted.

http://www.autopartswarehouse.com/shop_parts/mass_air_flow_sensor/volkswagen/rabbit.html


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## le0n (Jun 12, 2013)

bosch, e.g.: http://www.ebay.com/itm/Mass-Air-Flow-Meter-Sensor-MAF-AFM-OEM-336-60655-13A329-/370948931502?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AVolkswagen%7CYear%3A2007%7CModel%3AJetta&hash=item565e477fae&vxp=mtr


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