I had this same thing happen. I replaced the crank angle sensor and have been running perfectly ever since. Even though you buy new parts if they do not come from GM they are generic from Autozone and Advance. They will not last long but are cheap. $30 for crank angle sensor. At dealership it'll run you about $100+.

would yours sputter at all when the sensor was bad?? mine just cuts off completly and it does run for a couple seconds before it shuts down