Hello all, i have an SCT x4 flash tuner with lifetime tunes form bama and i also have the software to build my own tunes (have not built any yet still trying to figure a few things out first). Biggest issue right now is if i run my car stock tune there are no issues. The car is 1996 4.6 Manual 2v PI swapped with heads off of a 2011 crown vic with a dorman intake manifold, BBK shorties, k&n CAI, Pypes catted x-pipe 2.5" pypes m-80 exhaust. This problem im having was present wiht Npi head as well as now. Anytime I program a tune onto the ECM the car idles hi like 1100-1300rpm until warmed up then idles normal 800-950rpm. And as ive read a few others say the idle hangs between shifts and if i blip the throttle at a stop the rpms take longer to drop back to idle. I believe this is something with the IAC valve because if i unplug it and control the idle with my pedal the rpms do not hang. Any input would be great personally i am thinking i just need to replace IAC valve.