Bad MAF or Computer?

Pretty cut and dry, my truck has been running at a low idle, dying at red lights or in neutral. I have replaced the fuel pump, filter, MAF and sensor(with a used MAF), spark plugs and wires, cleaned the air system and the cat and muffler(i have a hole in my muffler) are next. Im pretty stumped because i keep chasing this problem and only get a temp fix. I will say that i can unlug the MAF sensor and it idles perfect, so what do you guys think? another bad MAF, bad computer or something im just looking over?

Sounds like a vacuum leak to me

just put a new a computer in, wasnt it. tore in the the idle air control valve to clean it and sure enough the gasket is screwed. so buying a new gasket and went ahead and bought a brand new IACV for 40 bucks on ebay, cant beat that badass deal. we'll see if that fixes the problem.

Well after cleaning take apart my idle air control valve cleaning it with carb cleaner and denatured alcohol and letting dry for 3 days. I get a new gasket, put it on, crank it and immediatly it revs to 4000 rpms then comes down to under 1000 rpms. I listen to the motor and im hearing a misfire pop inside the motor. For one this totally sucks after sinking so much money in it. Im completely lost what has caused this or even what it is. it was running chopping but not misfiring before i took all this apart and cleaned. Any ideas to help this out?