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.

Real-world scan data

Seen in

547

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P0425 scans

P042Ain 98.5% of scans

P0850in 97.8% of scans

P0704in 97.3% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P0425 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX