I would first check the output of your TPS. Engine off, live data on your ODBII scanner look at the TPS values as you go from the idle position to full throttle and back.

Next up is check for vacuum leaks, let me know if you need help.

Next is to figure out if you have actual misfires going on (you can start with the article in my signature). Are there and cylinders showing misfires when the engine runs crappy?

You can start it in the dark and mist all the ignition components to look for arcing.

Have you done the fuel pressure tests in the sticky?


George