OBD-II code · Powertrain (generic)
P0425 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.
Is it safe to drive with P0425?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyCat temperature sensor failed
- PossibleWiring or connector fault
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–2 h
- Emissions test
- Likely to fail
- Parts involved
- Cat Temperature Sensor, Sensor Wiring
Related codes
- P0422Main Catalyst Efficiency Below Threshold (Bank 1)
- P0423Heated Catalyst Efficiency Below Threshold (Bank 1)
- P0424Heated Catalyst Temperature Below Threshold (Bank 1)
- P0426Catalyst Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1)
- P0427Catalyst Temperature Sensor Circuit Low (Bank 1 Sensor 1)
- P0428Catalyst Temperature Sensor Circuit High (Bank 1 Sensor 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.