OBD-II code · Powertrain (generic)
P043C Catalyst Temperature Sensor Circuit Low (Bank 2 Sensor 2)
Catalyst temperature sensor at bank 2 sensor 2 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 P043C?
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)
- P0437Catalyst Temperature Sensor Circuit Low (Bank 2 Sensor 1)
- P0439Catalyst Heater Control Circuit/Open (Bank 2)
- P043ACatalyst Temperature Sensor Circuit (Bank 2 Sensor 2)
- P043BCatalyst Temperature Sensor Circuit Range/Performance (Bank 2 Sensor 2)
- P043DCatalyst Temperature Sensor Circuit High (Bank 2 Sensor 2)
- P043EEVAP System Leak Detection Reference Orifice Low Flow
- P043FEVAP System Leak Detection Reference Orifice High Flow
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.