get a hold of an obd II scanner. the one i have will show pending codes.....meaning the computer sensed something wrong but did not trigger the check engine light yet. I don't think my sympton is the same as yours since I seem to remember reading your other posts that your car shakes when you accelerate (mine doesn't shake at all).
also, if you disconnect the battery, you will lose what ever codes that are stored in the memory.
hope it helps