Ok so my buddy has a 03 4.8 silverado, he uses the same tuner as me, but ever once in a while his trucks idle will change, and during this time he can matt it, and only run up to about 2 grand, then after a lil while it will go back to normal. He doesn't have a huge budget would like to try to pinpoint, help if u have a ideal, idk to me sounds like a tps, but wut do yal think from expierence

 

Throwing any codes? Stock?

 

temp gauge do anything weird when this happens?

 

I don't think man, its just tuned stock, and ill ask him man

 

Under those conditions it would trigger a code. Or perhaps it is in the code history, scan for codes and let us know what you find.