[MeanWS6]

Ok, readers digest version on my winter beater. It's a 96's Olds 3.1, drove this thing for 80K+ miles without a SINGLE problem. Last month she started throwing P0300 (random misfire) and PO306 (cyl 6 misfire) at idle. So I replaced all the plugs, wires, fuel filter. Threw autotap back on and now cyl 2 was misfiring - so I replaced all six injectors, coil packs, ignition control module, PCM (went overboard but I just wanted this thing fixed)
Still same thing, took it to GM dealership and they said injector 5 was bad, so I replaced it again last night. Now I am getting random misfire codes and occasional misfire on other cylinders at idle and it is taking longer to crank over now.
At a loss rt now, only thing I have not replaced is the crank sensor - could that be the culprit. Or what about the wiring harness?
Guys have any other thoughts?
thanks