1. Idle Air Control Valve (IAC)
The IAC valve controls the amount of air that bypasses the throttle plate when the engine is idling. If the IAC valve is faulty or dirty, it can cause the engine to idle rough or stall.
2. Faulty Oxygen Sensor
The oxygen sensor measures the amount of oxygen in the exhaust gas and helps the engine control unit (ECU) adjust the fuel mixture accordingly. A faulty oxygen sensor can cause the engine to run lean or rich, which can lead to rough idling and stalling.
3. Dirty Throttle Body
The throttle body controls the amount of air that enters the engine. If the throttle body is dirty, it can restrict airflow and cause the engine to idle rough or stall.
4. Vacuum Leak
A vacuum leak can cause the engine to run lean, which can lead to rough idling and stalling. Check for vacuum leaks around the intake manifold, throttle body, and vacuum lines.
5. Fuel Pressure
Low fuel pressure can cause the engine to run lean and stall. Check the fuel pressure with a fuel pressure gauge to ensure it is within the specified range.
6. Spark Plugs
Worn or damaged spark plugs can cause the engine to misfire, which can lead to rough idling and stalling. Check the spark plugs and replace them if they are worn or damaged.
7. Mass Air Flow Sensor
The mass air flow sensor (MAF) measures the amount of air that enters the engine. If the MAF sensor is faulty or dirty, it can cause the engine to run lean or rich, which can lead to rough idling and stalling.
