Was driving and engine just shut off , will start but shuts off within 2 seconds.

Check to be sure the air intake is tight at air filter housing and throttle body and maybe needs fuel pressure test.

While I'm not sure of the correct answer to your problem, I suspect a vacuum leak. When I removed the clamp holding the airway duct elbow the to throttle body it spread open revealing a crack that was on the bottom side. This is down line from the MAF Sensor so unmetered air was entering the engine via the duct crack accounting for a significant vacuum leak. For reasons too lenghty to explain, I continued my process and replaced the Knock Sensor, MAF, an undamaged duct elbow (from the junkyard for $1, and a used ECM off Ebay. When I buttoned everthing up, it fired up at the first hit and hasn't missed a lick or stalled once. NOTE: The engine is still running like a sewing machine, but I've downloaded a trouble code for right & left bank O2 sensors (PO 130 & 150) as well PO171 (Mixture too lean). Could be the new (used computer). Autozone person told me today the used computer may need "flashing" for my particular VIN #. Anyway, that's where I'm at with it. (My contact info: ditycityinc@yahoo.conm) I just noticed that you posted this issue a very long time ago. Hope you've resolved the issue. If so, please let me know how you done it. Thanks.