08 equinox engine fires but won't stay running

[rlanders]

I have an 08 Equinox. I switched the key on while working on it in the garage (working on frontend) and I forgot to turn the key off and ran the battery all the way down. Battery would no longer hold a charge so I replaced it. Now the engine will crank and start but will only run for 2 or 3 seconds then dies. Any insight would be greatly appreciated.!!

 

[rlanders]

Turns out it was just a key issue the computer didn't recognize it. Used a different one and it works. Now we are having a different issue that I will post in a different thread.