well the guy i bought this car from for some weird reason turned up the idle to 1500 and so i turned it down to 1200. after it gets to 180-190deg it some how rises back up to 1500. when ses light comes on it will stay at 2000 in neutral till i stop. i got it checked at advance auto, yes its a 95 with obd1 but has obd2 input. the egr solenoid #1 malfunction popped up too. i have a cracked muffler, is that the code or is it something else?