A couple weeks back I did a tune up on my 95GT with new plugs, rotor and cap and MSD street fire wires. Well it started running like crap after that and had a surging idle, bad gas mileage, and wouldn't idle right. I found out the MSD wires were touching the headers so I changed them to the Ford Racing 9mm ones and the car ran fine after that and the mileage went back up but still had a little bit of an idle surge every now and then. Well now a week later it holds a steady idle when I first start it up but after it warms up and I drive it around for a bit the idle will surge and the car stumbles in low RPMs and it smells like its running rich but I also have a catless mid pipe so I don't know if that's it. The idle will also surge worse and up down between 700 and 1000rpm when I have all my accessories and subs on and the voltage gauge bounces back and forth a a lot too during this time. I've already cleaned my MAF and IAC, checked the TPS voltage which was fine, and reset the computer and base idle and nothing has helped. I pulled codes with a scanner and nothing came up either. I was wondering what else I could check and what might be wrong? Is my IAC just bad and needs to be replaced?