I'm stuck. Gotta one owner 91 GTA 305TPI thats still stock exept for a flowmaster on the tail. a few weeks ago it starts Idling low and dying out every now and then...runs like a bat outa hell 80% of the time and then seems to struggle the other 20. No rhyme or reason seemingly. It only has 60,000 miles on it. Wireing harness new by 2 years. Fuel pump and filters are good. New throttle position sensor & Relay switch. I cant detect any arching in the ignition and no code errors show up on scans. Could it be crankshaft position sensor? Duel Coil Issue? All input is appreciated...

Thanks 3rd genners.