OBD Guide

P21FD

Fuel Control System B Too Rich at Higher Load Bank 1

P21FD is an OBD-II diagnostic trouble code meaning: Fuel Control System B Too Rich at Higher Load Bank 1. Common causes: fuel injector malfunction, problems with the oxygen sensor (lambda probe). Estimated repair cost: $17–89.

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

Symptoms

  • Increased fuel consumption
  • Reduced engine power
  • Black smoke from the exhaust pipe
  • Unstable engine idling
  • Gasoline smell from exhaust

Causes

  • Fuel injector malfunction
  • Problems with the oxygen sensor (lambda probe)
  • Vacuum leak in the intake system
  • Fuel pressure regulator malfunction
  • Contamination or malfunction of the mass air flow sensor (MAF)

How to Fix

  1. Check the condition of the fuel injectors
  2. Diagnostics of oxygen sensors
  3. Check the intake system for vacuum leaks
  4. Check fuel pressure and pressure regulator
  5. Clean or replace the mass air flow sensor

Related codes

Error P21FD by Vehicle Brand

FAQ

What does the P21FD code mean?

P21FD is an OBD-II diagnostic trouble code that indicates: Fuel Control System B Too Rich at Higher Load Bank 1

What causes a P21FD error code?

The most common causes of P21FD include: Fuel injector malfunction; Problems with the oxygen sensor (lambda probe); Vacuum leak in the intake system; Fuel pressure regulator malfunction.

How do I fix a P21FD diagnostic trouble code?

To fix P21FD: Check the condition of the fuel injectors. Diagnostics of oxygen sensors. Check the intake system for vacuum leaks. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P21FD?

Yes, but get it checked soon

How much does it cost to fix P21FD?

The estimated repair cost for P21FD is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat