But my hot idle BLM has always been the same (142) before and after the header work.
So we know it wasn't causing a problem. The chip burner guesses as to the amount of fuel your motor needs at various loads and throttle openings. If his guess isn't exactly on,the computer will adjust based on what the oxygen sensor tells it. Don't concern yourself with not seeing a 128. It's not important. It could be a clue to a vacuum leak,but a low IAC number would be a much better indicator of that. It sounds like you're OK.