Catalyst Temperature Sensor (Bank 1, Sensor 1)
General electrical fault detected in the catalyst temperature sensor on bank 1 sensor position 1. The ECU uses this signal to manage heater control and protect the catalyst from overtemperature.
Affected components
- Cat temperature sensor
- Sensor wiring
Common causes
- High likelihood: Cat temperature sensor failed
- Medium likelihood: Wiring or connector 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
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.