* Idle Air Control (IAC) Valve: The IAC valve regulates the amount of air that bypasses the throttle body when the engine is idling. If the IAC valve is faulty, it can cause the engine to stall when you let off the gas pedal.
* Throttle Position Sensor (TPS): The TPS tells the engine control unit (ECU) how far the throttle plate is open. If the TPS is faulty, it can send incorrect signals to the ECU, which can cause the engine to run rough and stall.
* Vacuum Leak: A vacuum leak can also cause the engine to run rough and stall. Vacuum leaks can occur in a variety of places, including the intake manifold, hoses, and gaskets.
* Fuel Pressure: Low fuel pressure can also cause the engine to run rough and stall. Fuel pressure problems can be caused by a faulty fuel pump, a clogged fuel filter, or a leak in the fuel system.
To diagnose the cause of the problem, you will need to perform some tests. You can start by checking the IAC valve, TPS, and vacuum lines. If you find any problems with these components, you will need to replace them. If you are unable to find the source of the problem, you may need to take your car to a mechanic for further diagnosis.
