OBD Guide

P2C79

NOx Adsorber - Sulfur Limit Exceeded

P2C79 is an OBD-II diagnostic trouble code meaning: NOx Adsorber - Sulfur Limit Exceeded. Common causes: use of fuels with high sulfur content, nox adsorber regeneration system malfunction. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Increased fuel consumption
  • Reduced engine power
  • Check Engine light comes on
  • Unstable engine idling

Causes

  • Use of fuels with high sulfur content
  • NOx adsorber regeneration system malfunction
  • NOx adsorber contamination
  • NOx sensor malfunction
  • Problems with the fuel injection system

How to Fix

  1. Check the quality of the fuel used
  2. Perform forced regeneration of the NOx adsorber
  3. Check the operation of NOx sensors and the regeneration system
  4. If the contamination is severe, replace the NOx adsorber.
  5. Flush the fuel system

Related codes

Error P2C79 by Vehicle Brand

FAQ

What does the P2C79 code mean?

P2C79 is an OBD-II diagnostic trouble code that indicates: NOx Adsorber - Sulfur Limit Exceeded

What causes a P2C79 error code?

The most common causes of P2C79 include: Use of fuels with high sulfur content; NOx adsorber regeneration system malfunction; NOx adsorber contamination; NOx sensor malfunction.

How do I fix a P2C79 diagnostic trouble code?

To fix P2C79: Check the quality of the fuel used. Perform forced regeneration of the NOx adsorber. Check the operation of NOx sensors and the regeneration system. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2C79?

Yes, but get it checked soon

How much does it cost to fix P2C79?

The estimated repair cost for P2C79 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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