SCR Catalyst Incorrect
The ECM identifies the installed SCR catalyst as the wrong part — NOx conversion efficiency, NH3 storage capacity or coded part-number do not match the expected application. Typical after fitting a non-OEM SCR brick or after a coding error following replacement.
Affected components
- Scr catalyst
Common causes
- High likelihood: Incorrect or non-OEM SCR catalyst installed
- Medium likelihood: Coding mismatch after part replacement
Possible symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.