My Dad has a 2002 Jeep Liberty Sport V6 3.7L and when he comes to a stop at a stop sign or light, the engine will not idle and dies. He keeps it in neutral and revs the engine to keep it alive. This only happens once the engine is hot and will idle just fine when you first start the engine.
I changed the spark plugs, he had them already, and it didnt change anything. I accidentally broke the throttle position sensor, so I replaced it and it didnt change anything. I also took the idle air control valve off and cleaned the carbon up and it didnt change anything.

Anyone have any ideas as what to do next.
I do not have the ability to put a diagnostic system on it without paying a bunch of cash.

Appreciate the help