P0437
Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 1
Catalyst monitoring (emissions)
Generic OBD-II
Medium
What it means
P0437 means the catalyst temperature sensor on bank 2 (sensor 1) is reading an abnormally low voltage — usually a short to ground or an open in the circuit. This sensor monitors converter temperature for emissions control and doesn't affect how the engine runs, so the practical effects are a check-engine light and interrupted emissions monitoring.
Medium
Can I keep driving? The engine drives normally — this is a monitoring sensor, so the main consequences are a check-engine light and a possible emissions-test failure.
Common symptoms
What you'll notice
- Check-engine light on
- Possible failed or incomplete emissions readiness
- Usually no change in how the engine drives
Common causes
Most likely first
- Short to ground or low-voltage fault in the catalyst temperature sensor circuitLikely
- Faulty catalyst temperature sensor (bank 2, sensor 1)Common
- Chafed or pinched wiring grounding the signalCommon
- Poor or corroded connection at the sensorLess often
- Faulty ECM (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the fault is the bank 2 sensor 1 catalyst temperature sensor circuit low.
- Inspect the sensor's connector and wiring for a short to ground, chafing, or corrosion.
- Check the signal, reference, and ground at the sensor against specification.
- Compare the sensor's reading against actual exhaust temperature and the paired sensor.
- Repair the shorted wiring or replace the sensor as indicated. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0437?+
Yes — the catalyst temperature sensor monitors exhaust temperature and doesn't control how the engine runs. Repair it to clear the light and restore emissions monitoring.
Can I just clear P0437?+
It will return until the low-voltage circuit fault is repaired. Clearing only resets the light.
Related codes
Often seen with P0437
Read & clear P0437 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