1. Idle Air Control (IAC) Valve Issues: The IAC valve regulates the amount of air that bypasses the throttle plate, helping maintain the engine's idle speed. A faulty or dirty IAC valve can cause high idling and stalling issues.
2. Faulty Throttle Position Sensor (TPS): The TPS provides information about the throttle plate's position to the vehicle's computer (PCM). If the TPS is malfunctioning, it can send incorrect signals to the PCM, leading to high idling and stalling problems.
3. Vacuum Leaks: Vacuum leaks can cause various drivability issues, including high idling and stalling. Check for any loose or cracked hoses, gaskets, or vacuum lines that could be causing a vacuum leak.
4. Fuel Pressure Issues: Low fuel pressure can result in insufficient fuel delivery to the engine, causing it to idle high and stall when coming to a stop. Check the fuel pressure and fuel filter to ensure proper fuel flow.
5. Faulty Oxygen Sensor: The oxygen sensor monitors the exhaust gas and provides feedback to the PCM about the air-fuel mixture. If the oxygen sensor is malfunctioning, it can affect the PCM's ability to adjust the fuel mixture, leading to idle and stalling problems.
6. Transmission Issues: If the transmission is experiencing issues, such as slipping or not shifting properly, it can also cause the engine to idle high and stall.
It's recommended to have your vehicle inspected by a qualified mechanic to properly diagnose the root cause of the high idling and stalling issues.
