What causes P1166 on a Honda?

Open heater filament inside the sensor Blown A/F heater fuse Oxidized sensor connector Open heater control circuit Failed heater relay

How do I fix P1166 on a Honda?

Test heater element resistance — open means a new sensor Check the A/F heater fuse Inspect the connector for oxidation Verify heater command on cold start Replace the sensor; heater faults rarely heal

P1166 Air/Fuel Sensor Front Heater Circuit Malfunction

Q: What does P1166 mean on a Honda?

P1166 — Air/Fuel Sensor Front Heater Circuit Malfunction. Applies to Civic, Accord, CR-V, Odyssey.

Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: Civic, Accord, CR-V, Odyssey

What does P1166 mean on a Honda?

P1166 — Air/Fuel Sensor Front Heater Circuit Malfunction. This Honda-enhanced code applies to Civic, Accord, CR-V, Odyssey.

Common causes of P1166

Open heater filament inside the sensor
Blown A/F heater fuse
Oxidized sensor connector
Open heater control circuit
Failed heater relay

How to fix P1166

Test heater element resistance — open means a new sensor
Check the A/F heater fuse
Inspect the connector for oxidation
Verify heater command on cold start
Replace the sensor; heater faults rarely heal