P0166
O2 Sensor Circuit No Activity Detected Bank 2 Sensor 3
P0166 is an OBD-II diagnostic trouble code meaning: O2 Sensor Circuit No Activity Detected Bank 2 Sensor 3. Common causes: oxygen sensor malfunction, open or short circuit in wiring harness. Estimated repair cost: $56–167.
Symptoms
- Check Engine Light Is On
- Deteriorating fuel economy
- Increased level of harmful emissions
Causes
- Oxygen sensor malfunction
- Open or short circuit in wiring harness
- Poor contact in the sensor connector
- Problems with power or circuit ground
- ECU malfunction
How to Fix
- Check the integrity of the sensor wiring harness
- Check the contacts in the sensor connector
- Check the power and ground of the sensor circuit
- Replace the oxygen sensor if necessary
- Check the operation of the computer
Related codes
Error P0166 by Vehicle Brand
FAQ
What does the P0166 code mean?
P0166 is an OBD-II diagnostic trouble code that indicates: O2 Sensor Circuit No Activity Detected Bank 2 Sensor 3
What causes a P0166 error code?
The most common causes of P0166 include: Oxygen sensor malfunction; Open or short circuit in wiring harness; Poor contact in the sensor connector; Problems with power or circuit ground.
How do I fix a P0166 diagnostic trouble code?
To fix P0166: Check the integrity of the sensor wiring harness. Check the contacts in the sensor connector. Check the power and ground of the sensor circuit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0166?
Limited driving only, diagnose soon
How much does it cost to fix P0166?
The estimated repair cost for P0166 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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