Originally Posted by ???
I'm pretty much at a loss... sounds like you've tried everything.
maybe try unpluging your o2 and see if it runs better.
have you set the base idle? where you ground A and B (same as checking the codes) wait a min or so with the key on but not running. then unplug the IAC and the set timing plug thing, then start the car and set the idle for 450 rpm's (500rpm"s for an auto trans).... not sure if it will help much be its something free that can't hurt either way to try.
I have tried using that exact method, but you can't set the idle on a machine where the idle constantly changes (from 500-900 RPM). I can try unplugging the O2 but I suspect that will only put me into open loop and I'll run the same as when the car is cold. Only difference being that I might find some things that only happen in open loop when the engine is warm that may tip me off.