Just thought I would share my experience with all of you who have erratic idle and such other problems. When I bought this latest Camaro, it had two codes - MAT and 02 sensor, which were replaced, but I also replaced the coolant temp and coolant gauge sensors. This did not fix the idle, and we saw a vacuum leak around teh base of the TBI. Put a little sealer around that part with a new gasket, but didn't help much.

Finally today, I replaced pretty much all of my vacuum hoses, reset the IAC and the idle using the "paperclip trick", and the car idles PERFECT now! Just thought that I would share this with you guys that are going crazy like I was

 

Absolutely. I've been singing the "IAC/TPS/Minimu Air" song fo so long now that I must seem like a broken record. I have a cut-and-paste article that I usually post for these replies, since the problem is so common.