Dang. Too late to the party again. Glad you got it figured out though. I was certain it sounded like a typical Passlock issue, and not something else. The PCM doesn't care about the oil pressure, so that wasn't going to be it.
IT RUNS!! Someone on another forum provided me with a newer program version for my PCM with VATS disabled in their software. I flashed it, and the car finally stays running!