OBD Guide

P20EE

SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 1

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$167–556 (est.)

Symptoms

  • Increased fuel consumption
  • Reduced engine power
  • Check Engine Light Illuminates
  • Unpleasant exhaust smell
  • Increased NOx emissions

Causes

  • Contaminated or damaged SCR catalyst
  • Low level or poor quality of reagent (AdBlue)
  • NOx sensor malfunction
  • Problems with the reagent injection system
  • Engine control unit malfunction

How to Fix

  1. Check the level and quality of the reagent (AdBlue)
  2. Check the condition of the SCR catalyst for contamination or damage
  3. Check the operation of NOx sensors and their wiring
  4. Check the reagent injection system for leaks or blockages
  5. If necessary, replace the SCR catalyst or NOx sensors

Related codes

Error P20EE by Vehicle Brand