RE: P0131 and P0151
When it idles it sounds like the timing needs to be adjusted, like it's idling slow. I know the timing isn't something you can adjust on a '96. When I'm hard on it it sometimes really bogs down, has NO power for a couple of seconds and then the power kicks in and the truck will have a burst of power. The new TPS seems to have helped a bit. The truck will seem to run great for a while (really responsive to the pedal, lots of power) and then occasionally when I need to pass someone on the highway it will act up again and then trip the codes.