npelton13

My engine light came on the other day and its throwing the code P0456 Evap leak. When I looked under the hood, I found a big hole in the under side of this plastic part. Can anyone identify what this part is called? Its the one circled in red.

600whpA4

It is just a check valve.

npelton13

Could a hole in this "check valve" cause my engine light to come on and give me code P0456?

npelton13

Could a hole in this check valve also give me a loss of hp?

rovision

In my case, when this specific check valve cracked, I reached the point where I had a hard time starting the engine. After replacement, everything came back to normal.

lyleswk

Depends on how bad the leak is. If it a small leak, you will loose a little hp. If it is large, you will get the no start. easy replacement. Pretty sure the link below is the part.

http://www.ecstuning.com/Audi-B6_A4-...h/Check_Valve/

npelton13

Hey guys, I got the new check valve from ecstuning.com and installed it today. With the corroded valve, my car seemed real slow and sluggish. I probably got an increase of 20+ HP just from this new $15 part. Its back to performing like when I first got it. I also installed the aero wiper blade upgrade kit from ecstuning. These wipers are way worth the money!

jordonb

Glad to hear you got it sorted

Xbachelor

Had a similar problem and I came to find that additional valves were on their way too failing--in one case, the only thing keeping the valve in place was the tubing.