I have a 2002 GMC Sierra 1500 5.3l. My truck has a miss fire when heavy in the throttle. No codes when it is scanned.

Could be a clogged injector or simply bad fuel.when was your last tune up or service?

Try adding a Fuel injector cleaner & or your air filter.

If white smoke is visible, could be the PCV valve which will cause the engine to Bog Down & loose power. That is part of an annual/recommended tune up.

In the past month I changed all 4 O2 sensors, new plugs and wires,and fuel filter. I did have a code for 2 of the O2 sensors so I changed all 4. I put 350 miles on the truck since the plugs and wires, no codes have came up but still same problem.

Timing chain & or gears maybe worn. Cracked coil, p/u module in distributor may need to be replaced.

Is there a way to determine what is wore or needs replaced.

Thanks, I guess I'm going to start with the easiest and cheapest and go from there. I keep driving the truck in hopes it will throw a code