P0442 Chevrolet -

Question

would the "revving" it does have anything to do with the evap code po442, when idling in park it revs the tach goes back and forth up to one and back down, up down up down. sometimes it stalls especially when put in park and then the air con. turned off

Answer 1

Hi there,

It is possible. If the purge solenoid is stuck on, then it's kind of a vacuum leak but hidden. The solenoid opens at high speeds to pull the fuel vapor from the charcoal canister. If it's open when the car is idling it will cause the engine to run rich. The computer can try to adjust for that and cause the searching.