1996 cobra starts but dies instantly

[96Cobravert 3xblk]

1996 cobra starts but dies instantly. Changed o2 sensor yesterday BC of bank 1 sensor 1 code. Also was pulling a bank 2 running lean code. Im not sure exactly what code they were but I will post them when I find out. This isnt my car it is my roommates that I have been helping him with. I used to be on this forum along with my brotber when we had our fox bodies. Any help is most appreciated. Glad to be back

 

[wmburns]

First check all fuses. Look for a vacuum leak.

It may be quitting when the PCM switches from "open loop" to "closed loop" mode. This could be from a number of things such as:

• vacuum leak
• bad/disconnected IAC valve.
• bad MAF

What happens if the MAF is disconnected?

What happens if the throttle is held part way open during cranking?

 

[jgressley2003]

I don't know where you live, but if it's cold outside and it's doing this I'm gonna take a stab in the dark and say it's your coolant temp sensor.

 

[trinity_gt]

Is the "theft" light on the dash doing anything suspicious, like flashing?