I've noticed that my mustang has been acting kind of strange when it has been driven and then put into park. The idle is fluctuating from ~600(700)rpms-1000rpms and it does it slowly. I have the slightest clue as to what is the culprit to this issue is. IAC? TPS? Other? Thanks!
Here's some cheap trouble shooting. Unplug the TPS sensor while the engine is idling, if the engine idles down quickly & starts idling up & down the TPS is good. If nothing changes then the TPS is bad.