# My Eurovan's killing me!



## WannaCorrado (Apr 30, 2000)

I have to pass emissions within the next few days and the darn car is driving me NUTS.

it started with this:


> 16784 - EGR System: Malfunction
> P0400 - 35-00 - -


I cleaned the throttle body, removed the EGR valve and cleaned it out. it opens and closes with vacuum applied, as its supposed to. The solenoid is new also. Reset the codes, drove for 2 hours, the light comes back!!! Now, I have TWO codes 



> Address 01: Engine Labels: 021-906-259-AES.lbl
> Control Module Part Number: 021 906 259 P
> Component and/or Version: MOTRONIC M5.9 AT V03
> Software Coding: 00001
> ...


Can the EGR code be caused by an o2 sensor? I'll try and swap in another sensor tomorrow and see what happens, but this van's driving me insane!


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## Uwe (Jan 16, 2000)

I can't rule it out 100%, but I have my doubts that the Post-CAT sensor could cause the EGR code. 

-Uwe-


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## vwemporium (May 27, 2002)

::::: WARNING EMERGENCY FORUM ACTION MESSAGE:::::

THIS POST VACATED BY JACK TO PROTECT CONTENT FROM FALLING INTO THE GAPING HOLE OF THE VORTEX! :heart:

THIS SOLAR SYSTEM IS IN DANGER OF A BLACK-HOLE!
YOU TO CAN ESCAPE!
I CAN BE FOUND VIA THIS DHD STAR-GATE ADDRESS......
http://forums.ross-tech.com/member.php?18-Jack-European_Parts


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## FaithInMkIII2.0 (Jul 10, 2008)

make sure the egr passage through the intake isnt clogged with carbon soot...I have never seen an egr problem related to a post cat sensor unless it is due to high NOx i.e. P0420 cat efficiency. your egr valve is ok, now double check that it can actually pass the exhaust into the intake


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## WannaCorrado (Apr 30, 2000)

thanks for all the replies! 

Here is the update.. I took apart the intake manifold and cleaned out all the soot, as well as the carbon build up on the egr temp sensor. the car then got all except 2 readiness status to be OK.. So I FLEW to the inspection station, got a sticker and 15 minutes later... CHECK ENGINE IS BACK!!! 

same error code regarding EGR, but the oxygen sensor is still OK... 

So I swapped out the EGR solenoid AGAIN from my corrado - same part number - and lasted about a day until the CEL returned... 

I'm also thinking that it could be that the EGR temp sensor is off - when i do "set readiness" in the VCDS, the EGR portion doesn't show the EGR temperature, shows 0deg. 

Any way to check for EGR function separately?


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## WannaCorrado (Apr 30, 2000)

vwemporium said:


> Since you already tested the egr itself.
> 
> Well it would be a good start to check the vacuum noid and lines to the egr valve.
> 
> ...


 Thank you Jack. I'm kind of a novice, so I understood only half of this. 

The rear O2 sensor is OK - the readiness is now OK, and has been OK for days. 

EGR Solenoid is properly hooked up, I've tested two of them. 


I'll go play with the output tests - don't know how to use that function yet.


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## FaithInMkIII2.0 (Jul 10, 2008)

verify egr flow!!! is there a noticeable hesistation roughness when the egr valve is open passing exhaust to the intake? have you checked this? seems like a lot of wasted time checking valves and sensors that are probably ok...the egr passages clog with carbon and exhaust soot over time! you can clean em out with carb cleaner, seafoam and coat hangers


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## WannaCorrado (Apr 30, 2000)

that's the thing - I took EVERYTHING apart - all the way from exhaust to the intake, including the part of the intake that attaches the egr. I soaked the passages in carb cleaner, and used a toothbrush to make the parts look like new again...


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## FaithInMkIII2.0 (Jul 10, 2008)

WannaCorrado said:


> that's the thing - I took EVERYTHING apart - all the way from exhaust to the intake, including the part of the intake that attaches the egr. I soaked the passages in carb cleaner, and used a toothbrush to make the parts look like new again...


Thats all well and good but shiny parts wont make any difference if the insides are still clogged up... if you open the egr valve (as in apply vacuum to the valve with a vacuum/pressure tester, with the vacuum supply line plugged as not to cause a leak) with the engine running and it doesn't stumble a little then the egr isn't flowing enough exhaust..believe me, I have dealt with emissions repairs like this for a long time now, it is most common to see the passages clogged with carbon, can you hear air passing through when you blow through with compressed air? blow through the port in from the valve to the intake, listen for air goin into the intake..blow the other way and listen for air going into the exhaust..


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## WannaCorrado (Apr 30, 2000)

FaithInMkIII2.0 said:


> Thats all well and good but shiny parts wont make any difference if the insides are still clogged up... if you open the egr valve (as in apply vacuum to the valve with a vacuum/pressure tester, with the vacuum supply line plugged as not to cause a leak) with the engine running and it doesn't stumble a little then the egr isn't flowing enough exhaust..believe me, I have dealt with emissions repairs like this for a long time now, it is most common to see the passages clogged with carbon, can you hear air passing through when you blow through with compressed air? blow through the port in from the valve to the intake, listen for air goin into the intake..blow the other way and listen for air going into the exhaust..


I appreciate your replies, and sarcasm, but I think I'm quite clear that I opened everything up and made it shiny INSIDE.

EDIT: I'll do the vacuum and passage tests again, maybe even put it on video this time. I bought a mighty vac - will use that to test the egr while the engine is running...


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## vwemporium (May 27, 2002)

::::: WARNING EMERGENCY FORUM ACTION MESSAGE:::::

THIS POST VACATED BY JACK TO PROTECT CONTENT FROM FALLING INTO THE GAPING HOLE OF THE VORTEX! 

THIS SOLAR SYSTEM IS IN DANGER OF A BLACK-HOLE!
YOU TO CAN ESCAPE!
I CAN BE FOUND VIA THIS DHD STAR-GATE ADDRESS......
http://forums.ross-tech.com/member.p...European_Parts


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## WannaCorrado (Apr 30, 2000)

so it's been a year.. and I have to pass emissions again.. I would really love to solve this EGR problem this time.. 

I've checked that all passages are clear
I've replaced all vacuum lines
I checked EGR valve functionality by adding vacuum to it with a pump and engine hesitating.


What I don't know how to check is the EGR temp sensor. I want to blame it because when I do the "set readiness", it's the only item that never gets ready, and the correct temperature is not displayed - it shows either -48C or 0C.. Does anyone know what resistance I should expect on that sensor, so that I can test it with a multimeter?

I'm about to give up, get all readiness set and drive to the inspection station for a sticker.. again..


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## WannaCorrado (Apr 30, 2000)

I spent some time on the van today. The vacuum lines were run very differently than in the bentley, so I re-ran them. No difference, still cannot get readiness for EGR, all others pass.

here is before:










here is after:









and from another angle


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## WannaCorrado (Apr 30, 2000)

I WIN!


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## CoolAirVw (Mar 8, 2007)

WannaCorrado said:


> I WIN!


so what fixed it?


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## WannaCorrado (Apr 30, 2000)

wow, this was a long time ago.. previous owners connected the vacuum lines all wrong, took me too long to open the manual and figure out the proper routing and re-do it. for some reason, it still took 2 days to get the readiness set on the EGR, but check engine never returned till I sold the van a year later.


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