So i just bought a used A4 B7 3.2 quattro. I've been having some problems. First it threw the code p0455 evaporation control leak (gross). It also has trouble starting after i fill up with gas. and when i turn the car off sometimes i hear what sounds like air sputtering from under the middle of the car. any ideas? i've searched around and am thinking possible faulty purge valve on evap canister? just hoping its not an expensive fix.

 

Sounds like the evap line going to the tank under the passenger side is broken. It happens when someone who doesn't know any better puts the car on a lift. The line gets pinched between the body and the lift arm.

 

thanks for the reply. i'll just have to get it fixed by a mechanic. do you know if this affects the throttle at all? feels like my car has some lag when i step on the gas.

 

Check the EVAP control valve. Test it by removing it and trying to blow through it. If air will pass through, it's junk. It's about a $25 dollar part. I,m not sure of exactly where it is located, but it should be up on the intake manifold.

When these things are gone, the car will start hard and run kind of shitty.

Good luck

 

It's most likely the evap purge valve (N80), it's stuck open. I had the same thing happen to my 2.0T, it was a pain to start after fueling. I'm not sure if the 3.2 uses the same exact part, I got mine from the dealer for $18. Hardest part was removing the original one, a crimp clamp was used and was a pain to remove. The new one was installed within 5 minutes using a screw type clamp.

 

It could.... because if the line is broke open and the purge valve is cycling like normal it will create a vacuum leak.

Its really easy to see too.... You can get on one knee and look under the passenger side near the front tire wheel well. What your looking for is to see if the plastic trim under the car is broken and mangled. The line is visible even if the plastic is not broken.

A faulty purge valve usually will not create a driveability issue, The evap parameters for emissions will fail and the car will run slightly more rich.