Catalyst Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1)
Catalyst temperature sensor at bank 1 sensor 1 reads in range but plausibility check fails — slow response or stuck reading.
Affected components
- Catalytic converter
- Exhaust temperature sensor
Common causes
- High likelihood: Sensor drift
- Low likelihood: Sensor element aged beyond calibration window
- Low likelihood: Sensor mounting loose - signal damping
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.