Was driving today when the check engine light came on. Opened the hood and checked the engine: it was still there. Seriosly though, there was no change in drivability or anything like that, and the gas cap was tight. However, I have been noticing that after a warm start the RPMs drop like the engine is about to stall ( sometimes it has ) then rebound several times before it idles normally. Any thoughts? I'm not the most mechanically inclined person, but I do the basic maintainence and can follow instructions. Once the problem is fixed, is there any way to reset the light without using a special tool? Aamco advertises that it offers free evaluations on the check engine light; do they clear it alsofor free does anybody know. Any imput would be greatly appreciated!