If your vehicle is showing engine starts but immediately stalls out, here are the most likely causes and the parts you'll need to fix each one.
If the engine computer cannot accurately measure incoming air, it will start on a pre-set fuel map but immediately stall. This frequently happens if the sensor is left unplugged after checking or replacing the air filter.
A disconnected PCV hose, torn intake boot, or failed intake gasket allows unmetered air into the engine. This leans out the air-fuel mixture so severely that the engine cannot sustain an idle.
Carbon buildup can jam the IAC valve or the throttle body plate. This starves the engine of the bypass air it needs to stay running when your foot is off the gas pedal.
If the vehicle doesn't recognize the transponder chip in your key, the security system will allow the engine to start for 1-2 seconds before intentionally cutting off the fuel injectors.
There may be just enough residual fuel pressure in the lines to start the engine. However, if the pump or its relay fails to keep running, the engine will quickly starve for fuel and die.
If the Exhaust Gas Recirculation (EGR) valve gets stuck open by carbon debris, it acts like a massive internal vacuum leak of exhaust gases, choking out the engine at idle.