P0425
Catalyst Temperature Sensor Circuit Bank 1 Sensor 1
Catalyst monitor / emissions
Generic OBD-II
Medium
What it means
P0425 means the computer detected a circuit fault in the bank 1, sensor 1 catalyst temperature sensor, which monitors converter temperature. This is an emissions-monitor code with little effect on how the car drives, but it keeps the check-engine light on and can fail an emissions test. It usually traces to the sensor or its wiring.
Medium
Can I keep driving? Safe to drive; this is an emissions-monitor fault that rarely changes how the car runs, though it can fail an emissions test.
Common symptoms
What you'll notice
- Check-engine light on
- Usually no noticeable change in drivability
- May fail an emissions/readiness test
Common causes
Most likely first
- Faulty catalyst temperature sensor (bank 1, sensor 1)Likely
- Open, shorted, or corroded wiring in the sensor circuitCommon
- Loose or corroded connector at the sensorCommon
- Failed engine control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm it's the bank 1 sensor 1 catalyst temperature sensor circuit.
- Inspect the sensor connector and wiring for damage or corrosion.
- Check the sensor's resistance/signal against temperature spec with a scan tool.
- Replace the catalyst temperature sensor if it's out of spec with good wiring. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0425?+
Yes — it's a temperature-sensor circuit fault that rarely affects drivability. Repair it before an emissions test.
Can I just clear P0425?+
It will clear, but returns until the catalyst temperature sensor or its wiring is repaired.
Related codes
Often seen with P0425
Read & clear P0425 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX