DTrizzle

Wondering if any of you guys could help me out with a problem ive been having. My car has been running rough for awhile now. Seems like a misfire to me. turning the AC on makes it much worse. It never stalls, just stutters. The only code it is throwing is a MAF problem code. I have changed all the plugs, wires, cap, dist. rotor, MAF sensor, IAC sensor, and even tried a different ECU. Ive replaced all the vacuum lines, and double checked to make sure all the intake tubing is sealed properly. The timing is correct as well. Sometimes it runs smooth so I believe it is an electrical issue. Could it possibly be the cat? Im kinda out of ideas, as are my mechanic friends. Any help is greatly appreciated. Thanks guys.