What it means
A general electrical fault on the catalyst temperature sensor at bank 2 sensor 2.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The catalyst temperature sensor at bank 2, sensor 2 reports temperature information for the exhaust catalyst on the engine’s second bank. The control module monitors its electrical signal and sets P043A when it detects a general circuit fault, without specifying whether the signal is open, shorted, or otherwise out of range.
Common causes
Most likely first.
- Catalyst temperature sensor failure
- Open or short in the sensor wiring
- Corroded or loose sensor connector
- Fault in the control module
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
How to diagnose it
- Use a scan tool to confirm P043A, check for related sensor or wiring codes, and note the freeze-frame conditions when the fault appeared.
- With the exhaust cool, locate the bank 2 sensor 2 connector and inspect it and the nearby harness for looseness, corrosion, heat damage, or chafing.
- Compare the bank 2 sensor 2 live temperature reading with the engine and exhaust conditions, and compare it with the corresponding sensor on the other bank if available.
- Check the sensor circuit for continuity, shorts to ground or power, and secure terminal contact using the vehicle wiring diagram.
- If the wiring and connections are sound, test the sensor and its circuit against the manufacturer's specification before considering a control-module fault.
Common fixes
- Reconnect and secure the bank 2 sensor 2 connector.
- Repair damaged or corroded wiring and terminals in that sensor circuit.
- Replace the bank 2 sensor 2 catalyst temperature sensor if it fails testing.
- Repair or replace the control module only after confirming the sensor circuit and sensor are sound.
Can I keep driving?
The code does not usually cause limp mode, so a short, gentle trip may be possible if the engine runs normally and there is no strong exhaust smell. Avoid heavy loads and arrange a repair soon because emissions monitoring may be impaired; stop if the vehicle develops serious running problems or an intense sulfur smell.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.