Okay I bought a 94 Dodge Dakota 5.2 that back fired and had a hard time staying running at any RPM. The plugs were fouled out. I changed them out and they found out again. I put a new timing chain in it. "The old one had three quarters of an inch of play". (Reset timing) I have also put a new crank sensor, throttle positioning sensor, new plugs, cap/rotor, Magneto, wires, and tps in it and the cat was removed. (Before I bought it) the pre-cat O2 sensor is still in. And ran a fuel system cleaner and stabilizer through the tank.


Now the truck idles great and drives pretty good when it's cold. But once the truck warms up it won't get past 2800 RPMs and then it backfires and stalls out. It will fire right back up and idle decent and will move as long as you don't give it gas. As soon as it cools back off it runs great.

 

Unplug the front O2 sensor, see if it runs any better.