CEL need assistance over!

[AudiA4Turbo22]

Hey guys i just changed 3 Check valves and some hosing, but recently got a CEL and the code is: Purge Valve Flow Malfunction! i thought it was a check valve or something, but i guess not! any ideas? can it be that i put a check valve the wrong way


EDIT: Only Comes on when the A/C is on!!!!!!!!!!!!!!!!!!!!!!!!!

[windyctyaudi]

Yes its possible, double check to make sure they are on right and clear the code. if it comes back try and swith them around one by one to see it the code goes away

[AudiA4Turbo22]

goin to the freakin shop tomorrow i'm so pissed!!! i spent $720 last week on the freakin car for brakes, new suspension, oil change, freon, Axles, etc. and 2 days later CEL and the window regulator dies! i'm gonna go crazy!

[PRY4SNO]

Be patient, these things like to go when the weak link collapses.

Then you'll have a solid car again.

For a while.

[AudiA4Turbo22]

^^haha hope so!

[AudiA4Turbo22]

someone help!

[old guy]

Did you check to make sure you installed the check valve in front of the N80 purge valve in the correct direction as in the picture I PM'ed you last week? Also, start your car wait about 30 seconds and then check to see if the N80 purge valve is cycling. You should hear a faint clicking from the valve. If you don't have a stethoscope try using a screwdriver. Touch the blade of the screwdriver to the N80 and place your ear on the ball end of the handle. You should be able to hear the valve rapidly clicking on and off. If not, you may have a defective N80 purge valve. If it is clicking but the purge code continues to return, try taking out the N80 valve and checking it for debris. It may be clogged.

Good luck!

[FourRings80]

check N80
http://forums.audiworld.com/a4gen2/msgs/1063792.phtml

[AudiA4Turbo22]

n80 WAS CHECKED AND IT WORKS FINE, IT IS RELATED TO MY AC BUT HAVE NO CLUE AS TOO WHAT!

[old guy]

n80 WAS CHECKED AND IT WORKS FINE, IT IS RELATED TO MY AC BUT HAVE NO CLUE AS TOO WHAT!

Are you getting the DTC from a generic code reader or is it a true vag code? If so, what is the exact code?

[AudiA4Turbo22]

^^true VAG code, forgot the numbers, but it said emissions control, and N80 Purge flow malfunction!

[old guy]

I am at a loss to see the connection between your AC and the N80 flow issue. I would refer you to the link FourRings80 provided for several diagnostic checks on the N80. Read through all the connected dialog, particularly Diagnosticators input. How did you confirm that it wasn't an N80 problem?

[old guy]

Here is a link to a little more info on how the whole purge system works. It may give you a little insight as to other possibilities that can cause incorrect flow. for example, the LDP not opening properly to allow the flow through the charcoal canister to the N80 to purge the fumes. Clicky click Read post 5.

Again, Good luck!

[AudiA4Turbo22]

i took it to my uncle's shop and per auto data pro, we tested it using an ohm meter, and it spiked and ran correctly, and it clicks just the same as always!

[AudiA4Turbo22]

thanx for the link guys very interesting info, i think ima test it myself to be sure!

[brewmastr]

check your evap hoses for restriction, one of the downfalls of evap logic comes into play when there is an obstruction in the line, even though the n80 may be operating the computer dosent understand why it is not seeing any flow, the logic behind your code is quite simple, the evap system is seeing no flow, if it was seeing flow all the time you would have a leak code most likely, so if the valve is operating start checking your lines for restriction.

[AudiA4Turbo22]

^^ty! theres just so much to check!

[brewmastr]

well once you really understand the codes logic it really gets simple, either the valve is not energizing and opening up which it sounds like you replaced so you know its working ok, or there is a blockage in the evap system usually after the pressure system, usually you will get a fresh air vent code if it is before the pressure sensor when obstructed. oh btw maybe old guy or diagnosticator can help you out with this type of test with the vag-com as i have not had the lucky fortune of playing with evap on our cars, but have done alot on benz and nissans. but what will help you is being able to monitor the evap pressure sensor and having the specified sensor value of when the system is flowing, so you can compare this to what your actual values are, im thinking you got some crud in your line, when you pull off the hoses to your n80 is there any charcoal in the line to maybe indicate the canister is coming apart? if you replaced the n80 and you still got the code look real close for restriction anyhwhere pressure sensor forward in the system. why it really helps to monitor the pressure sensor is you can work back from the engine disconnecting hoses in the evap system, and when you see the pressure sensor fall to whatever the spec for atmospheric pressure is, you know the obstrcution is forward of that point.

[AudiA4Turbo22]

^^thank you man, come to think of it a T connector did snap while i was working, maybe a part of it flew in there somewhere!