uh-oh. my check engine light came on just the other day. everything seemed to be running fine excpet at idle. there seemed to be a slight shutter while at a light, but when i was moving there seemed to be no problem. i was leaving work today and noticed the light was off and the shutter was gone. great! what a fantastic car, it fixed itself. on the way home there seemed to not be so much pick up and my turbo gauge was way into the left, even at full throtle it barley crossed the line. could this be a vacuum leak? and is it dangerous or harmful to keep driving it until i can fix the problem? any help would be great.