Ok so i've read the whole thread on the weird misfire but heres the thing. My car is misfiring randomly across all cylinders. Mostly number three but that's against the point. I've replaced every sensor on the motor, every piece of ignition, PCM, all of it! complete tune up... been in the shop several times... nothing. same misfire across all cylinders. runs like crap. no power... I'm starting to lose it. before you ask, its not all delco stuff but i didn't have issues with aftermarket stuff till recently. I've cleaned the egr, cut off the cat, scraped the corrugated tubing... honestly short of ripping the motor out IDK what else to do... any ideas?

 

Did you do th basics Like plugs and wires?

 

I had a miss on the 3800sc in my Fiero that turned out to be a broken pin on the coil pack. Get a multimeter or power probe and check the wiring from the coil pack to the computer for shorts. have some one shake the harness when testing to find if you have a broken wire.