OBD Guide

P231B

Cylinder 8 Air-Fuel Ratio Imbalance - Adjustment At Limit During Balance

P231B is an OBD-II diagnostic trouble code meaning: Cylinder 8 Air-Fuel Ratio Imbalance - Adjustment At Limit During Balance. Common causes: dirty or faulty injectors of cylinder 8, problems with the ignition system in cylinder 8. Estimated repair cost: $22–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–167 (est.)

Symptoms

  • Unstable engine operation
  • Reduced engine power
  • Increased fuel consumption
  • Check Engine Light
  • Vibrations at idle

Causes

  • Dirty or faulty injectors of cylinder 8
  • Problems with the ignition system in cylinder 8
  • Low compression in cylinder 8
  • Vacuum leaks in cylinder 8 pipes
  • Oxygen sensor malfunction

How to Fix

  1. Check and, if necessary, replace the injector of cylinder 8
  2. Check the spark plug and ignition coil of cylinder 8
  3. Measure compression in cylinder 8
  4. Check the tightness of the intake manifold and vacuum lines
  5. Check the functionality of the oxygen sensors

Related codes

Error P231B by Vehicle Brand

FAQ

What does the P231B code mean?

P231B is an OBD-II diagnostic trouble code that indicates: Cylinder 8 Air-Fuel Ratio Imbalance - Adjustment At Limit During Balance

What causes a P231B error code?

The most common causes of P231B include: Dirty or faulty injectors of cylinder 8; Problems with the ignition system in cylinder 8; Low compression in cylinder 8; Vacuum leaks in cylinder 8 pipes.

How do I fix a P231B diagnostic trouble code?

To fix P231B: Check and, if necessary, replace the injector of cylinder 8. Check the spark plug and ignition coil of cylinder 8. Measure compression in cylinder 8. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P231B?

Limited driving only, diagnose soon

How much does it cost to fix P231B?

The estimated repair cost for P231B is $22–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat