P1166
Air/Fuel Ratio Sensor 1 Heater Circuit Malfunction
P1166 is an OBD-II diagnostic trouble code meaning: Air/Fuel Ratio Sensor 1 Heater Circuit Malfunction. Common causes: air/fuel ratio sensor malfunction, open or short circuit in the sensor heating circuit. Estimated repair cost: $28–89.
Symptoms
- Check Engine light comes on
- Increased fuel consumption
- Unstable engine operation at idle
- Reduced engine power
- Increased level of harmful emissions
Causes
- Air/fuel ratio sensor malfunction
- Open or short circuit in the sensor heating circuit
- Damage to the sensor wiring harness
- Heating circuit fuse or relay failure
- Problems with the engine control unit (ECU)
How to Fix
- Check the condition of the sensor and its connector
- Check the integrity of the sensor heating circuit
- Check the fuse and relay of the heating circuit
- Replace the faulty sensor if necessary
- Check the operation of the engine control unit
Related codes
Error P1166 by Vehicle Brand
FAQ
What does the P1166 code mean?
P1166 is an OBD-II diagnostic trouble code that indicates: Air/Fuel Ratio Sensor 1 Heater Circuit Malfunction
What causes a P1166 error code?
The most common causes of P1166 include: Air/fuel ratio sensor malfunction; Open or short circuit in the sensor heating circuit; Damage to the sensor wiring harness; Heating circuit fuse or relay failure.
How do I fix a P1166 diagnostic trouble code?
To fix P1166: Check the condition of the sensor and its connector. Check the integrity of the sensor heating circuit. Check the fuse and relay of the heating circuit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P1166?
Yes, but get it checked soon
How much does it cost to fix P1166?
The estimated repair cost for P1166 is $28–89. Actual cost depends on your vehicle, location, and labor rates.
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