SCR NOx Pre-Catalyst Efficiency Below Threshold (Bank 2)
SCR NOx Pre-Catalyst Efficiency Below Threshold (Bank 2): the control module has detected this fault condition.
Affected components
- Scr pre catalyst
Common causes
- High likelihood: Pre-catalyst thermally aged
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
Related codes
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.