OBD-II code · Powertrain (generic)
P0437 Catalyst Temperature Sensor Circuit Low (Bank 2 Sensor 1)
Catalyst temperature sensor at bank 2 sensor 1 below lower plausibility — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P0437?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Temperature Sensor
Related codes
- P0427Catalyst Temperature Sensor Circuit Low (Bank 1 Sensor 1)
- P042CCatalyst Temperature Sensor Circuit Low (Bank 1 Sensor 2)
- P043CCatalyst Temperature Sensor Circuit Low (Bank 2 Sensor 2)
- P0434Heated Catalyst Temperature Below Threshold (Bank 2)
- P0435Catalyst Temperature Sensor Circuit (Bank 2 Sensor 1)
- P0436Catalyst Temperature Sensor Circuit Range/Performance (Bank 2 Sensor 1)
- P0438Catalyst Temperature Sensor Circuit High (Bank 2 Sensor 1)
- P0439Catalyst Heater Control Circuit/Open (Bank 2)
- P043ACatalyst Temperature Sensor Circuit (Bank 2 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.