Help with rough and no idle condition.?

I have a 97 Dodge Dakota with a 3.9l v6. On warm or hot days, after driving the truck for 30 minutes or the engine won't idle on own. it'll idle rough, then sooner or later die. It only does this on warm days, after being driven at operating temperature for a while. It doesn't set an engine code. I installed a new coil, spark plugs, cleaned the idle air speed motor, and cleaned the throttle body. Since it only does this after being hot, I assume an electronic device is heat soaking and breaking down. Has anybody ever ran into this? I think it must be the TPS or AIS motor, but I don't want to just throw parts at it beyond what I have already done. What do you suggest?

I have to add that I have a degree in vehicle systems technology, and now work for a Dodge dealer. I just want other opinions. One man says replace the TPS, one says AIS. neither have run into this exact problem before.

I have seen this some times,only once on me although was it the AIS,all the other times it was a bad o two sensor causing this,it was just telling the computer to shut the gas down on it,but if I was you id have it scanned 1st just to make sure,auto zone can and will do this,and its free,then you,ll know for sure,whats causing it,good luck with it.

been a certified mechanic for 36 yrs.

check the EGR valve

take out your o2 sensor and clean it well. check all wires going to and from o2 sensor. this is an O2 sensor problem, most probably. If cleaning it doesnt help, I could really replace the sensor.