My bad - the air temp sensor will be telling the ECU some wild tale about how cold or hot it is, and screwing with the fuel air mixture. Swap with new or one from salvage or dismantler. It should show up as IAT (Intake Air Temp) on a data reading scanner, so you could see if values were anywhere reasonable. Auto parts store should connect scanner for free.

That may be but I'm wondering if we don't have a vacuum issue coming from restricted flow through one of the cats perhaps causing the elevated reading on the IAT. It's been know to happen. Putting it all together could certainly cause the bad response of idle.

my guess is the two issues are unrelated...

Just unplugged mine, the scanner thinks it is -40F when the sensor is unplugged (which would equal open, or broken wires). ECU would adjust mixture and other things accordingly. So a data reading scanner will tell you if sensor is bad. Does not make truck rev high at idle when unplugged.

Could extract IAT sensor and let it hang in the engine bay, like guys do that have those cone air filters. Then you could pour water on it or hair dryer it to see temp change.

[Solved] Fuel Pump was the problem
 

I replaced the fuel pump, the inlet strainer fuel pump was clogged and needed to be replaced. I had to replaced the Fuel pump as well.. 65 bucks for the motor at Autozone

Airtex fuel pump, #E3240, about $65,

Are you still displaying any codes?