need help idle issue

[usnfenix]

ive had an idle problem ( car is automatic) for some time now that is steadily getting worse. heres the whole deal sry in advance if its a bit too read but i need help. never had any problem untill after i installed my bbk intake manifold and a summit 85mm throttle body. i used felpro gaskets on the intake and i i reused the sensors from my old throttle body. my car started having a very slight miss at idle but nothing at all to worry. a month went by and i did long tube headers with AIR delete, ( re used stock o2 and car is still not tuned) soon after my idle problem got worse and worse by the day, and got really bad at cold starts. i would start the car and it would almost die, i would have to rev it just to get it to settle into a normal pattern. it would take a min to warm up and idle correctly. then got worse and one day in the rain my car started mifireing so bad i could not go above 20mph and i limped it home, blinking ses light. i replaced the o2 sensors and car ran fine. now my idle problem is back and got progressively worse as it did before, same very rough idle on start, today i started it and watched the rpm go from 400 then jump to 700 then go back down and up till i reved it and it settled on 500. at stoplights car will noticebly miss at idle and it gets so bad i think it will die on me sometimes, i will have to hold down the gas pedal at stoplights to keep it going. i replaced the o2 again this time with denso and no change. ive cleaned the MAF and no change. i unplugged the MAF during idle and it seemed to get a little better and get worse as i plugged it back in but it was so slight i could not be sure. heres my guesses and looking for input from you guys. car is only throwing the AIR delete codes and the no cats codes you get from doing lt's.
car idles at about 600 in park and in drive but at stop idles at 500 but dips low almost to 450

MAF sensor?

bad idle air controller? or the stock IAC not good for my bigger aftermarket TB? ( this one is what im leaning towards the most)

engine coolant temp sensor ( noticed the wires going into it are bare and exposed and seem to be barely hanging on to the sensor)

or just really really need a tune for the lt install and the air delete

**
update i just went out to my car and let it idle and unplugged the IAC and the was no change what so ever, you could still hear and see the motor miss and shudder and when i plugged it back in there was no change, no sounds change no change in shuddering, i know you can check a MAF on some cars this way but can you check an IAC this way on ls1's? does this mean my IAC is bad or nto good for an aftermarket 85mm tb?

[cammed goat]

You need a tune for the AIR delete. Once you start removing vital engine accessories, you need a tune so the ECM can compensate for the deleted accessories.