ok i have a 96 chevy c3500 with a 454 in it it broke down on me so i changed out ing switch and now when i try and drive it it boggs down at 2 rpms i have change fuel pump plug wires the sencer in the oil pan i just cant figuer out what is makeing it do it if any one can help me out please let me no thanks
first things first. I would have the truck put on a computer. see if you have any codes.
But as far as a best guess would be from what you say. I would be leaning towards one or both of the cataletic converters.