That still sounds like a very narrow range of options that it could be.
Sounds like an anti theft option has been set. What chip are you running?
Also, over the last 25 years I've had this happen to me a few times, always after I've done some form of engine work and the culprits included:
Once left MAF unplugged
Once left MAF unhooked to inlet pipe to turbo
Once left the vacuum block on top of the throttle body loosly bolted (massive vacuum leak)
Car will start and run for 2 seconds with all the above mistakes.
