Hi,

Just wondering if anyone has any clue as to the problem with Cel P0455 on an 98 Audi A4 quattro. Here is the diagnostic report from a code reader:

P0455
Evap Emission sys leak detected (gross leak / no flow)

misfire ok
fuel sys ok
comp component ok
cat mon inc
htd catalyst n/a
evap syst mon ok
sec air system n/a
a/c refrig mon n/a
oxygen sens mon inc
oxygen sens htr
egr system mon n/a

I also smell gasoline inside the cabin (definitely different from exhaust gasses). Also, when I get near empty and gas light comes on, after a car restart, gas level goes back to a little over empty and gas light turns off (a definite move in the needle, not just parking on inclines, etc.). Happened about twice before I decided to refuel.

I have checked as many vacuum hoses and had a roaming mechanic do the same and no hoses were leaking (but this wasn't a very complete check).

Any ideas? I dont feel like spending over a 100 bucks just to diagnose this at the dealership.

Thanks!

 

start with checking your gas cap make sure it isnt lose and make sure it isnt leaking also check your EVAP Canister Purge Regulator Valve.. thats were i would start.. 2 most common things to fail to my knowledge

 

Thanks man. I forgot to mention I got the same problem when I lost my gas cap (however cel read large leak, now reads a little different). Replaced it with an aftermarket one. Could that really be it?

 

UMMM.. idk i mean if it was $2 gas cap from autozone then i mean i wouldnt trust it.. but i dont trust anything from autozone.

i mean that i couldnt answer just go to a hole in the wall place that does state inspections and ask them to test your gas cap for you for a couple bucks serioulsy it takes like a minute to do it.

if it is ok clear the fualts close the gas cap real good. and i just noticed i looked over it you say you can smell fumes in your car maybe you have an EVAP line under your car got dragged when you were leaving some place and put a small hole in it .. idk man its hard to test evap systems without specialty tools like a smoke meachines are legit take the gas cap off put on the smoke machine start pumping it in next thing you know have smoke coming from somewhere if there is a leak!! and if it doesnt leak from anywhere while you are doing the smoke leak test its the gas cap.

 

Did u find out what it was? Im having the same exact problem but when i put gas and i tirn it on it goes back of..and i need to cranck it a lot and step on the accelerator till it goes on and keep high rpm for about a min then in fine wont happen till i put gas again..any ideas of what could it be?

 

Rony, did you figure out what your problem was? I have the same problem as you. After I fill the tank I have to crank for about 20 secs giving it a ton of gas to get it to start and then keep giving it gas for at least a minute. I have checked my codes and I get both Evaporative Emissions Incorrect Purge Flow P0441 and Evaporative Emissions System Leak P0455. I guess I will start with the gas cap and then check for hose leaks, moving on to replacing the EVAP purge regulator valve if all else fails.

 

I have the 455 code also. Did a smoke test and had smoke coming out of the filter of the leak detection pump. I have read replacing the pump did not fix the CEL. I also had smoke comimg out of the brake assist can. Is that ok?
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