P043ACatalyst Temperature Sensor Circuit Bank 2 Sensor 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Some engines – mainly diesels – measure the temperature at or in the catalyst with a thermistor in a voltage divider instead of only modelling it; most makers report exhaust temperature sensors under P0544 ff, P2031 ff or P2080 ff instead. Sensor 2 of bank 2 is a second, further downstream catalyst temperature sensor on the side without cylinder 1. P043A is the general circuit fault, used where the module does not separate low and high. No manufacturer document available to us uses this code; the description follows CARB, which requires input circuits to be checked for circuit faults and plausibility, and the comparable exhaust temperature sensors.
- What you may notice
- Check engine light on
- Usually no noticeable change (substitute value from the model)
- Diesel: filter regeneration distorted or blocked, possibly further codes such as P2459 or P0420
- Likely causes
- LikelySensor faulty (element or lead broken by heat or vibration)
- LikelyHarness chafed or scorched at the exhaust, connector corroded
- PossibleConnector loose or pins pushed back
- RareEngine module input
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.