i have a 95 jimmy 4.3 W installed new cam sensor, 2 new knock sensors, map sensor, 2 O2 SENSORS, NEW THROTTLE POSITION SENSOR. NEW COIL new plugs, rotor, cap, wires, new spider,new fuel pump and this animal still idles rough and missfires and sets 300 code can anybody help

Have you done a compression test? If so, what did you come up with? You said it is rough at idle, does it smooth out as the RPM's increase?

I've had P0300 DTCs generated when three rocker arm studs were pulled off the heads. Obviously, it idled poorly and ran rough.

It's not always a sensor or ignition component. Like BigBlue advised, check the mechanical condition of the engine.

does anybody know what what the cylinder compression should be on 1995 jimmy 4.3 W with 20.000 miles on it