Hopefully you guys can help me narrow down this issue I've been having. I have a 2004 SVTF that has had a weird habit of hanging revs when coasting with clutch in to a stop or when in neutral. The revs will hang at about 1100 - 1500 and then after a few seconds will eventually return to the correct idle speed. I have replaced the TPS and IACV and the issue persists. I recently tuned the car through RPS, and the tune has had no effect on this specific behavior. The tune fixed numerous other weird things about how the car runs, but this is the only thing I can't seem to figure out. I've tried a few different part numbered TPS's and all of them do the same thing. I've cleared the ECU 3 times since tuning in case it needed to "relearn" the parts, but nothing seems to fix this. Let me know what you think.