I thought I would post this an that it may help someone . I started with a steeda tune with a ateeda cold air kit and off road H pipe. My car is a 2005 mustang GT and it just would'nt idle right as soon as I programmed he car . I paid no mind to it and of course the dealer that sold me the tune denied anything was wrong on there part. I then returned the programer. I then purchased a vortech base kit that came with a sct tuner with two tunes . The car would not idle bat at times just die! This was getting agrivating and no one had any awnsers to help me fix it . I have relied on only myself on fixing and repairing my cars, but since programers are the locked by the dealers that sales them then I was stuck. After many calls to the programer and checking my very meticulas instal for fixes . I found nothing was wrong. I then gave up on the tuner and just idled my car to 1350 rpms driving and 950 rpms idle to get it back to normal .
The best fix is to have a custom tune on the dyno. Hope this helps !