P21F8
Fuel Control System B Too Lean at Idle Bank 1
P21F8 is an OBD-II diagnostic trouble code meaning: Fuel Control System B Too Lean at Idle Bank 1. Common causes: air leaks in the intake tract, malfunction of oxygen sensors. Estimated repair cost: $17–89.
Symptoms
- Unstable engine idling
- Power Loss
- Increased fuel consumption
- Check Engine light comes on
- Dips during acceleration
Causes
- Air leaks in the intake tract
- Malfunction of oxygen sensors
- Clogged fuel injectors
- Weak fuel pump
- EGR system malfunction
How to Fix
- Check the intake tract for air leaks
- Check the operation of oxygen sensors
- Clean or replace fuel injectors
- Check fuel pressure and pump operation
- Diagnose the EGR system
Related codes
Error P21F8 by Vehicle Brand
FAQ
What does the P21F8 code mean?
P21F8 is an OBD-II diagnostic trouble code that indicates: Fuel Control System B Too Lean at Idle Bank 1
What causes a P21F8 error code?
The most common causes of P21F8 include: Air leaks in the intake tract; Malfunction of oxygen sensors; Clogged fuel injectors; Weak fuel pump.
How do I fix a P21F8 diagnostic trouble code?
To fix P21F8: Check the intake tract for air leaks. Check the operation of oxygen sensors. Clean or replace fuel injectors. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21F8?
Yes, but get it checked soon
How much does it cost to fix P21F8?
The estimated repair cost for P21F8 is $17–89. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat