I have had this issue a couple of times, when it gets wet for more than a few days, my car throws a check engine light, and i finally managed to get it pulled, it came on when i was on my was home from work, and i was about 2 miles from a checker. The code i am getting is a P0442, Evaporative control system leak detected (small leak). this ONLY happens when it gets rainy and crappy out for more than a few days, and i have noticed that it will idle low as well. its an 05 impreza RS, the drivetrain is stock, no intake exhaust, or tune. Any ideas on what could be causing this?
That code is usually a gas cap that isnt tight enough or a faulty one... Nothing to worry about... over half the cars that throw check engine lights that i run the scanner on throw this code... doesnt affect anything
On my lexus rx300 had that bouncy idle too but the check eng. light didn't come on so I bought a new gas cap from toyota and no more idle problem. the seal may be old and hardened thru winter and the pressure is off.
