By any chance is the theft light lit up on the dash usually happens when replacing the battery…there are a couple ways to get this to go off…leave the key on for to mins…with the doors shut… after 10 mins turn off the key.. take it out of the ignition and get out and close the doors…with the key fob lock then unlock the doors.. should be off…or put your key in the door lock…make like your going to unlock the door but hold in the unlock pos. For 30 seconds… my car was doing the same thing after all that It would start then stall in a few seconds…my fuel pressure regulator line was loose and I had a cracked vacuum line also my air filter box was open and the MAF was exposed to the elements…there are many things (this is actually the reason I bought mine for dirt cheap with 100k original miles on it) also check out the fuel system cut off in the trunk.. just because it's not tripped don't mean it's not shut off…it could be corroded or just dirty and the corrosion will trip it! Good luck folks hope some of this helps someone out, !!