Allen........ No codes, No Check engine light, what I'm trying to find out is what determines where the IAC should be, I know it's controlled by the computer, but what are the factors that move the IAC in or out ???? & I agree it is a PITA.
As for mod's........ headers and that's about it, all the EEC (Electronic Emissions Controls) are hooked up, as are the sensors. The engine is installed in a 90 Chevy truck (w/4l60E) and it will run with the big boys. It's great off idle and very strong.
I'll try what you said about make'n the computer re-learn the new part, I'll let you know. By the way we now have a scanner and I want to put some pic's on here, what the procedure for doing so.