05 WRX idles over 3500 RPM sporadically
Car runs very well normally (it is stock) but once in a while in warm weather- A/C usually on but sometimes with it off- it will race at idle up to 4000 RPM's. (All guages indicate normal temp and pressure) Have had a dealer check it for codes and nothing found. Check engine light came on and private mechanic cleared codes by replacing Elec vent valve and canister assy damaged by gravel roads. Also repaired wiring as noticed and cleaned mass air flow assy. Still races at idle but only after driving for about an hour and now check engine light is on again. It will not do this if I start it and drive it a short distance to the dealer. Totally frustrated but love the car and afraid I will have to give it up if I cannot solve this problem.