I have a 97 K1500 with a 5.7. the other day the truck started missing and lost power. I changed the fuel filter, cap and rotor. Still no better. It idles fine soon as you step on the gas it bogs down and backfires through the intake and exahust. I checked the tps and the idle control both are ok. Also I checked the fuel pressure and its 60psi. any help would be great

 

How old are the plug wires?

 

The plugs and the wires have about 3 thousand miles on them.

 

how many miles does the truck have? could be plugged fuel injectors

 

How exactly did you check the TPS and the IAC sensors?

 

Sounds alot like like a plugged Catalytic Convertor.

 

I think I found the problem. I went back to the fuel pressure and tested it again. I had the truck running and after a couple of minutes it droped to about 20psi than when I hit the gas it went to almost zero.