[ericmb55]

I have read the threads that have suggested that the TPS or the CTS could be the problem. I haven't really thought about the timing chain or gears. The truck has 130K on it. I have changed the tires back to 265/75/16. I had put 285/75/16 on it and it just became sick. No power at all and I was getting 9 mpg at times. I checked last night and it got 15mpg. This is much better but it is still not running right. It seems to go through the normal high idle while warming up but it surges during idle after warm up. It's almost like it can't decide how much fuel it needs. I have also noticed that it will surge while driving if it is put under a load such as going up a hill. I'm thinking TPS but I don't know how to set it right if I change it. Any thoughts?