Bad PCM
I don't know Chevy's warranty policy but I would be very surpised if the PCM had a special case 8 year warranty.
https://ls1tech.com/forums/showthrea...=Rebuilt+Motor
The Auto Tech checked all the grounds and fuses. Made sure everything was connected right and came to the conclusion that it might be a bad PCM.
1 - Was the car (and PCM) running O.K before the motor was modified?.
If yes then you need to ask yourself what might have happened in all the fiddling.
These ones are hard to track down, but I would be more inclined to spend some time wiggling, pulling on the engine harness whilst the car is running to see if you can get the fault to occur, it might be a loose GND, it maybe a wire has been pinched or pulled somewhere that is intermittantly loosing continuity.
I'm not suggesting that is cannot be the PCM, but maybe try to save yourself a few $$ and spend sometime trying to track down what might be a 'simple' wiring issue.
Good Luck.


