OBD Guide

P21F6

Fuel Control System B Too Lean Off Idle Bank 2

P21F6 is an OBD-II diagnostic trouble code meaning: Fuel Control System B Too Lean Off Idle Bank 2. Common causes: air leaks in the intake tract, malfunction of bank 2 fuel injectors. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Unstable engine operation
  • Increased fuel consumption
  • Detonation (knock) during acceleration

Causes

  • Air leaks in the intake tract
  • Malfunction of bank 2 fuel injectors
  • Low fuel pressure
  • Bank 2 oxygen sensor malfunction
  • Contamination or malfunction of the air flow sensor

How to Fix

  1. Check the intake tract for air leaks
  2. Check the operation of bank 2 fuel injectors
  3. Measure fuel pressure
  4. Check the condition of the oxygen sensors
  5. Clean or replace the mass air flow sensor if necessary

Related codes

Error P21F6 by Vehicle Brand

FAQ

What does the P21F6 code mean?

P21F6 is an OBD-II diagnostic trouble code that indicates: Fuel Control System B Too Lean Off Idle Bank 2

What causes a P21F6 error code?

The most common causes of P21F6 include: Air leaks in the intake tract; Malfunction of bank 2 fuel injectors; Low fuel pressure; Bank 2 oxygen sensor malfunction.

How do I fix a P21F6 diagnostic trouble code?

To fix P21F6: Check the intake tract for air leaks. Check the operation of bank 2 fuel injectors. Measure fuel pressure. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P21F6?

Yes, but get it checked soon

How much does it cost to fix P21F6?

The estimated repair cost for P21F6 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat