Heated Catalyst Efficiency Below Threshold (Bank 2)
Heated (electrically warmed) catalyst on bank 2 fails efficiency monitoring. In addition to standard catalyst aging, faults in the catalyst heater control or supply can cause this code.
Affected components
- Heated catalyst
- Catalyst heater
- Oxygen sensor downstream
Common causes
- High likelihood: Catalyst aged or contaminated
- Medium likelihood: Catalyst heater circuit fault
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
- A drive cycle may be required after repair
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.