Danielle - No check engine light and no error codes? Any signs of sluggish acceleration or any other symptoms before it died. I can't count the cat out but I would lean toward something electrical - it dies and it restarts right away. First thought would be the crankshaft position sensor. If the PCM (engine computer) looses it's signal the engine looses timing data it needs to run. The system is designed to kill the engine so it won't over pollute. Isn't the EPA a wonderful agency. Heaven forbid you pollute a little more than designed. Who cares if you're in heavy 80mph traffic. KILL THAT ENGINE NOW. GM ignition switch recalls get all the news for the same engine kill scenario but don't mess with the EPA.....sorry, it's aggravating.
The sensor will often fail without generating a code and a check engine light. Number two on my list would be the camshaft sensor for the same reason. Both sensors can be tested but tough to nail a fault down when it's intermittent. Inspect connections, verify wire continuity and reference voltage. If all looks good change one at a time. They cost around $40.
Last edited by Cougar41; 06-25-2014 at 04:18 PM.