P0442, P0455 with intermittant high idle
For about a week, usually in the evening, my idle stays high, 1100-1800, quickly hitting the pedal doesn't seem to help and I've checked for a sticky cable. I jumped on the forum today and read to turn the key on and off 3 times. I came up with P0420 (catalyst system efficieny below threshold (bank 1)), P0442 (evaporative emission control system leak detected (small leak)) , P0455 (evaporative emission control system leak detected (gross leak)), and P1281 (I've determined may be the thermostat (after market)). I've triple checked all vacuum lines with carb cleaner. Now, how do I determine what is leaking or not working? Is it the leak detection pump? the duty cycle purge valve?, the charcoal canister? etc... It's a 4x2 with 215k on the v6 motor. Last summer I found out my #2 cylinder head gasket was leaking. I steel seal twice and it seems to be holding. Any help is appreciated.