I have a 2008 Impreza and when ever I come to a stop light or just driving slowly in a parking lot. The RPM's surge from idle up to 2000rpm. This is with the clutch all the in and even the brake on. It does it everytime when appoaching a stop light and will continue to do it after i am stoped. If I put it in neutral it will stop(I have the 5sp). Has anybody had this problem?
I have had the same issue since new. The dealer stated the it was apart of the emissions system. The computer recognizes a rich condition due to the clutch being depressed and idles the engine up to clear the cylinders. I hope the engine control module reprogramming might take care of this issue. It's quite annoying.