I have a 2001 Ford Explorer sport. Recently, when the vehicle is warmed up and you put it into park, the idle drops and gets rough. Occasionally the vehicle does die. It does not appear to do this when the car is cold though. I think I had something similar to this years ago when it was still under warranty and I think they said it was the PCV valve. Does this make sense?
The PCV valve is about the most simple component on an engine to check.
Pull it out from the valve cover and shake it. If it rattles, it’s good.
Another test is (with the engine at idle) to put you thumb over the end of the valve and see if there is air suction. If there is, it’s good.
You MAY have a faulty IAC motor or a dirty throttle body.
I’ll check it out.
Sounds to me like it may be your IAC Valve.