P21A3

Symptoms

• Unstable engine idling
• Misfire in cylinder 8
• Loss of engine power
• Increased fuel consumption
• Check engine light comes on

Causes

• Faulty injector of cylinder 8
• Problem with ignition coil or spark plug cylinder 8
• Vacuum leak in the area of the intake manifold of cylinder 8
• Low compression in the eighth cylinder
• Problems with the oxygen sensor or its wiring

How to Fix

1. Diagnostics and checking the condition of the spark plug and coil of cylinder 8
2. Checking the performance of the fuel injector of cylinder 8
3. Compression testing in the eighth cylinder
4. Checking for vacuum leaks around the intake manifold
5. Diagnostics of oxygen sensors and their wiring

Related codes

Error P21A3 by Vehicle Brand