P21FA
Fuel Control System B Too Lean at Idle Bank 2
P21FA is an OBD-II diagnostic trouble code meaning: Fuel Control System B Too Lean at Idle Bank 2. Common causes: air leaks in the intake tract after the mass air flow sensor, malfunction of oxygen sensors (lambda probes). Estimated repair cost: $17–111.
Symptoms
- Unstable engine idling
- Floating speed
- Power Loss
- Increased fuel consumption
- Check engine light comes on
Causes
- Air leaks in the intake tract after the mass air flow sensor
- Malfunction of oxygen sensors (lambda probes)
- Problems with the fuel pump or fuel pressure regulator
- Dirty or faulty fuel injectors
- Malfunction of the mass air flow sensor (MAF)
How to Fix
- Check the intake system for air leaks
- Check oxygen sensor readings
- Measure the pressure in the fuel system
- Clean or replace fuel injectors
- Check the performance of the mass air flow sensor
Related codes
Error P21FA by Vehicle Brand
FAQ
What does the P21FA code mean?
P21FA is an OBD-II diagnostic trouble code that indicates: Fuel Control System B Too Lean at Idle Bank 2
What causes a P21FA error code?
The most common causes of P21FA include: Air leaks in the intake tract after the mass air flow sensor; Malfunction of oxygen sensors (lambda probes); Problems with the fuel pump or fuel pressure regulator; Dirty or faulty fuel injectors.
How do I fix a P21FA diagnostic trouble code?
To fix P21FA: Check the intake system for air leaks. Check oxygen sensor readings. Measure the pressure in the fuel system. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21FA?
Yes, but get it checked soon
How much does it cost to fix P21FA?
The estimated repair cost for P21FA is $17–111. Actual cost depends on your vehicle, location, and labor rates.
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