P0428
Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1
P0428 is an OBD-II diagnostic trouble code meaning: Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1. Common causes: temperature sensor wiring shorted to power, faulty catalytic converter temperature sensor. Estimated repair cost: $6–889.
Symptoms
- Check Engine light is on
- Possible engine power limitation (emergency mode)
- The smell of a burning catalyst (with real overheating)
- Increased fuel consumption
- Possible ringing or knocking noise from under the catalyst if there is real damage
Causes
- Temperature sensor wiring shorted to power
- Faulty catalytic converter temperature sensor
- Real catalyst overheating due to a rich air-fuel mixture
- Misfires (unburned fuel is burned in the catalyst)
- Damaged thermocouple wiring insulation
- ECU malfunction (rare)
How to Fix
- Read all codes - the presence of misfire or air/fuel mixture codes will indicate the root cause
- Check the actual temperature sensor readings: do they correspond to the operating temperature?
- Check the wiring and connector of the sensor for short circuit and integrity
- Replace the temperature sensor if it is confirmed to be faulty
- Clear all associated codes (misfire, rich mixture)
- Allow the catalyst to cool and retest
- Reset the code and check for reoccurrence
Related codes
Error P0428 by Vehicle Brand
FAQ
What does the P0428 code mean?
P0428 is an OBD-II diagnostic trouble code that indicates: Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1
What causes a P0428 error code?
The most common causes of P0428 include: Temperature sensor wiring shorted to power; Faulty catalytic converter temperature sensor; Real catalyst overheating due to a rich air-fuel mixture; Misfires (unburned fuel is burned in the catalyst).
How do I fix a P0428 diagnostic trouble code?
To fix P0428: Read all codes - the presence of misfire or air/fuel mixture codes will indicate the root cause. Check the actual temperature sensor readings: do they correspond to the operating temperature?. Check the wiring and connector of the sensor for short circuit and integrity. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0428?
Do not drive — repair immediately
How much does it cost to fix P0428?
The estimated repair cost for P0428 is $6–889. Actual cost depends on your vehicle, location, and labor rates.
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