Stalls at operating temperature, various speeds

What is your question?

My Probe stalls after about 20-30 minutes of driving. No coughing, missing, no warning, just shuts off like the key was turned off. Seems heat related. Runs great until it reaches this point, whatever it is causing it to die. Have replaced temp. sensor switch, fuel filter, coolant fan switch, coil wire. Thought it only happened with AC on at first, but no, did it to me without AC on. Once this happens, it will not restart until it has sat for awhile, like an hour. Then starts right up and runs like a champ until reaches that point again and just shuts off. When first bought few weeks ago, wouldn't pass smog. Diagnosis was temperature sensor switch. Said it had "open loop" and dumping excess fuel causing gross polluter emission readings. Temp switch replaced, passed smog with great numbers, well below requirements. I know it probably needs professional electrical and fuel system diagnosis, but want to try all I can before I go pay too much in case it is something I can fix.