Ok here is the deal i have a 98 with a 2.4l and it had bad acceleration and when it is cold out on deceleration the rpm jumps up and down and the car idles high. The deal said it might be the cam carrier, be for the issue started the exhaust pipe broke at the head and my brother was driving it around for about a week . if any one could point out the problem and give me an idea on how to fix it it would be much appreciated.

thanks,
justin