Code result
P21FC
Fuel Control System B Too Lean at Higher Load
Moderate severity
What it means
Secondary fuel control loop B on bank 1 reports a lean condition at higher load. Lean at high load typically points at fuel pressure shortfall, restricted injectors, or charge-air leak.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Fuel pressure drops under load
highOne of the most commonly reported causes for this code — check this first.
Charge-air leak after turbo
mediumA plausible cause — test and verify before replacing parts.
Related help
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