Evap system P0456 - very small leak detected

[earhythmic]

Still trying to hunt down an erratic idle and system too rich at idle issue. Just installed brand new injectors today and upon a spirited test drive on the freeway my car stumbled and died at the next stop light. It restarted eventually and drove home fine. Pulled codes and got what is in the title. Would a “very small leak detected” cause a car to just stall out? I’m at the point now of just throwing parts at the car, any input on where to start?

TIA!

Edit: upon brief googling, I found the EVAP canister/solenoid could cause that code, and would make sense why I’m getting erratic idling and random backfires if the thing is stuck open. Part number 06h906517h or 06H133781CL for the complete assembly. Anyone have any experience with such things?

[flowhigh]

Still trying to hunt down an erratic idle and system too rich at idle issue. Just installed brand new injectors today and upon a spirited test drive on the freeway my car stumbled and died at the next stop light. It restarted eventually and drove home fine. Pulled codes and got what is in the title. Would a “very small leak detected” cause a car to just stall out? I’m at the point now of just throwing parts at the car, any input on where to start?

TIA!

Edit: upon brief googling, I found the EVAP canister/solenoid could cause that code, and would make sense why I’m getting erratic idling and random backfires if the thing is stuck open. Part number 06h906517h or 06H133781CL for the complete assembly. Anyone have any experience with such things?

What did you use to pull the code? Check to see if the fault frequency matches that of your the issues you said.

N80 valve with just a small leak detected normally shouldn't cause full blown stumbling. it could even be your n80 or your gas cap.

If anything it might say large leak detected with what you described.

[earhythmic]

What did you use to pull the code? Check to see if the fault frequency matches that of your the issues you said.

N80 valve with just a small leak detected normally shouldn't cause full blown stumbling. it could even be your n80 or your gas cap.

If anything it might say large leak detected with what you described.

I used VCDS to pull the code.

Just did some more poking around and system testing with VCDS. Ran a test on the N80, clicks on and off as it should. Even took it off to try to blow in it, I couldn’t. Sounds like a lot of sucking coming from the PCV. Did the oil cap test and there’s A LOT of suction trying to remove it. Could THAT be causing the car to stall out? If so, still dunno why I’d get the P0456

[SlvrArrw]

I just got that code this morning. Will be interesting tracking it down.
Possible culprits: PCV, N80, gas cap, loose connections.

Sent from my Pixel 3a XL using Tapatalk

[earhythmic]

I just got that code this morning. Will be interesting tracking it down.
Possible culprits: PCV, N80, gas cap, loose connections.

Sent from my Pixel 3a XL using Tapatalk

I have a new PCV being delivered today, my fingers are crossed tight that it solves my issues. Stupid me thought since I had a B8.5 I had a revised version...ha! 185k miles on this original PCV, I guess it’s about time it failed regardless of revisions.

In combing through all of the internet reading about PCV symptoms, seems like it may be the cause for all of my issues: occasional lack of power, odd idling but perfectly fine on-throttle, weird thumping backfire sounds sort of like an exhaust burble but more “something-sounds-like-it’s-breaking”y. Strangely I’ve never thrown the typical codes that point to a failing PCV.

[unmarkedA4]

Buy a smoke tester on Amazon 110 bucks plug it in and it will show you.

Mine was the vacuum line from the gas cap to the tank. Ended up accessing it through a hole we have in the trunk.


Sent from my iPhone using Audizine Forum

[flowhigh]

Even with a faulty n80 you won't be able to feel the failure blowing into it. The evap system can sense very minute drops in pressure. When I changed the n80 in the b7 I couldn't tell whether or not it was bad. Blew till the back corners of my jaws hurt but code never came back after I changed in the new one.

[TLR_0125]

I have a new PCV being delivered today, my fingers are crossed tight that it solves my issues. Stupid me thought since I had a B8.5 I had a revised version...ha! 185k miles on this original PCV, I guess it’s about time it failed regardless of revisions.

In combing through all of the internet reading about PCV symptoms, seems like it may be the cause for all of my issues: occasional lack of power, odd idling but perfectly fine on-throttle, weird thumping backfire sounds sort of like an exhaust burble but more “something-sounds-like-it’s-breaking”y. Strangely I’ve never thrown the typical codes that point to a failing PCV.

Was the PCV your issue? I had a smoke test done (no leak), the new revised PCV installed, and N80 replaced and my small evap leak appeared again after about 300 miles. The mechanic said possibly related to the charcoal canister. Wasn't even aware that was a thing. Also was curious if this had anything to do with oil consumption or not?