Throttle Position Sensor problems

[arreis1002]

I have a 2001 GMC Sierra 1500 4.8L

 

I have had the same issue multiple times now. If I let the truck idle

 

for any length of time, especially when the weather hot, it goes into

 

"Reduced Engine Power" mode and I can do nothing but limp to the side of

 

the road. I have taken it to my local mechanic (who I've used for over

 

20 years) and each time it throws a TPS failure code. My mechanic is at

 

a loss as he's never seen this happen before and it has happened 4 or 5

 

times to me. The TPS has been replaced each time.

 

Any ideas?