Rough idle - coding a large vacuum leak in EVAP system

[denman]

can anyone tell me the best way to attack "large leak" diagnostic. I have replaced oxygen sensors/mass airflow sensors/charcoal canister and checked all hoses connections. Cant seem to find leak - and it idles very rough.

I'm at a loss here - thinking maybe catalytic needs to be replaced.

Any suggestions here ??

[thenofjboy]

did you get it scanned; what codes did you get???

[denman]

I scanned it before sensor replacements....will scan again. Unfortunately, my battery needs to be recharged (replaced the alternator) and will do so when at full charge

[Silveravant]

Really don't think catalytic converter has anything to do with a large vacuum leak in the EVAP systerm.

[Axis]

Smoke test

[bfunk1414]

can anyone tell me the best way to attack "large leak" diagnostic. I have replaced oxygen sensors/mass airflow sensors/charcoal canister and checked all hoses connections. Cant seem to find leak - and it idles very rough.

I'm at a loss here - thinking maybe catalytic needs to be replaced.

Any suggestions here ??

im having the same issue. I havent tried what u did to yours but try this http://www.audizine.com/forum/showth...+found+problem

I will try that with mine tomorrow. Maybe the leak comes from there

[SamsonKnight]

Yes, smoke test is the best way to test. But if you don't have a smoker, inspect the gas cap, n80, then the leak detection pump.