P21A0
Cylinder 5 Air-Fuel Ratio Imbalance
P21A0 is an OBD-II diagnostic trouble code meaning: Cylinder 5 Air-Fuel Ratio Imbalance. Common causes: dirty or faulty fuel injectors, air leak in the intake manifold. Estimated repair cost: $17–89.
Symptoms
- Unstable engine idling
- Increased fuel consumption
- Loss of engine power
- Misfire in cylinder 5
- Check Engine Light Illuminates
Causes
- Dirty or faulty fuel injectors
- Air leak in the intake manifold
- Problems with the ignition system (plugs, coils)
- Oxygen sensor malfunction
- Low compression in cylinder 5
How to Fix
- Check the condition of the fuel injectors
- Diagnose the ignition system of the 5th cylinder
- Check the tightness of the intake tract
- Test oxygen sensors
- Measure compression in cylinders
Related codes
Error P21A0 by Vehicle Brand
FAQ
What does the P21A0 code mean?
P21A0 is an OBD-II diagnostic trouble code that indicates: Cylinder 5 Air-Fuel Ratio Imbalance
What causes a P21A0 error code?
The most common causes of P21A0 include: Dirty or faulty fuel injectors; Air leak in the intake manifold; Problems with the ignition system (plugs, coils); Oxygen sensor malfunction.
How do I fix a P21A0 diagnostic trouble code?
To fix P21A0: Check the condition of the fuel injectors. Diagnose the ignition system of the 5th cylinder. Check the tightness of the intake tract. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21A0?
Yes, but get it checked soon
How much does it cost to fix P21A0?
The estimated repair cost for P21A0 is $17–89. Actual cost depends on your vehicle, location, and labor rates.
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