If your vehicle is showing engine starts then immediately dies, here are the most likely causes and the parts you'll need to fix each one.
The vehicle's security system fails to recognize the key's transponder chip. It allows the engine to start briefly using residual fuel pressure but immediately cuts the fuel injectors or spark to prevent theft.
Extremely common after checking or replacing the air filter. If the intake hose is left loose or the MAF sensor is left unplugged, unmetered air enters the engine, causing it to run too lean and stall instantly.
Carbon buildup blocks the small passages that allow air into the engine at idle. The engine gets enough air to fire while cranking, but suffocates as soon as you let off the key.
The fuel pump primes the system when the key is turned on, providing enough pressure for an initial start. However, a weak pump or failing relay cannot maintain the continuous pressure needed to keep the engine running.
If the exhaust gas recirculation valve gets jammed open by carbon debris, it acts like a massive internal vacuum leak. It dumps exhaust gases into the intake at idle, suffocating the engine immediately after it catches.