Try to make this short. Comin home from bar, car starts cutting in and out. Complete loss of power, speedo, gas gauge , tach all go to zero then after a second, its running again. By the time I get back to my buddy's place it will barely run. Like the PCM has a light switch turning it on and off. Next morning, nothing. The engine will turn over but not even a spudder of ignition. The SES, gas gauge and tcs don't come on. Only the seatbelt and service vehicle like come on. Complete loss of PCM communication from the car.
Before you think the PCM has **** the bed, let's flash forward a week ahead. New PCM in hand, I drop it in, same thing. Brain dead. Checked the grounds and batt power at the PCM harness and they all checked out. Grounding where it should be and getting 12v too. Stock 02 SS with only 56k miles. Someone got something I haven't checked yet???

 

happened to me one time .. the power steering oil was leaking over the alternator and WTF.. the alternator failed !! .. I changed the alternator and everything back to normal !! ..

I'm not good in troubleshooting in these cars but this an idea to check

 

It's not the alt. I've already checked the grounding point over ther and it was clean. Thanks for the input though

 

Check battery terminals, they can corrode and cause many weird problems, sometimes runs good, sometimes don't even start.

Make sure they are clean and tightened, use a metal brush if needed.