Rough Idle

Check the following components or conditions:

• Stored trouble codes.
• Throttle sensor operation.
• Ignition system and timing.
• Idle speed.
• Air intake system for leaks.
• Fuel pump control system (turbo).
• By-pass Air Control System (BAC) operation.
• Air Control Valve (ACV) operation.
• Coolant thermosensor.
• Atmospheric pressure sensor.
• Airflow meter.
• Check idle mixture and fuel pressure.
• Fast idle RPM.
• EGR valve operation.
• Intake air temp. sensor on intake pipe or chamber.
• ECU operation.
• Engine compression.