frustrating05silverado

This has been an ongoing and frustrating problem, also transient and extremely inconvenient. My 05 Silverado has been transiently dropping into "low power mode" and throwing the code for the pedal position sensor. The problem started out by occurring about once a week and would resolve with a restart. Eventually, it stopped resolving and I took it in for service. A fair amount of money later, the pedal and position sensor and throttle body have been replaced, the ground has been cleaned up (Ohio truck=rust), and the problem appeared to have resolved itself for about one month. It has now started dropping into low power mode again and resolving with a restart about once per week. Does anyone have any suggestions as far as what I can try to do/replace/fix at this point? It's had a good diagnostic computer hooked up to it, and my mechanic isn't Chip Foose, but he's no slouch. The only other fix that he can think of that hasn't been tried is replacing some of the wiring. Is this the right direction? Any ideas are appreciated. Thank you.

oldchevy

I would try cleaning the ground again or connecting the ground to a better spot or maybe even directly to the battery. I would try this before spending any more money on it.