well went out driving, drove for about 1 1/2 hours and let the car rest for about 3 hours. I started it back up and then 5 mins later I started to get low idle (after shifting hard) 1 hour later it went back to normal but then I shifted hard (high rpms) and it came back. I just recently replaced my serpantine belt. The old one was too loose. its a 2002 mtx. Dont know whats going on, thanks.