P0166 - O2 Sensor Circuit No Activity Detected Bank 2 Sensor 3
P0166 Possible Causes
- Faulty Heated Oxygen Sensor Bank 2 Sensor 3
- Heated Oxygen Sensor Bank 2 Sensor 3 harness is open or shorted
- Heated Oxygen Sensor Bank 2 Sensor 3 circuit poor electrical connection
How is the P0166 code repair?Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
What is the cost to diagnose the P0166 code
Labor: 1.0The cost to diagnose the P0166 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
How much do you know about cars?
Take the AutoCodes.com automotive tests and turbo-charge your car repair knowledge
When is the code detected?Current amperage in the rear heated oxygen sensor heater circuit has no activity.
- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust
P0166 MeaningThe rear heated oxygen sensor (or sensor 3 for some vehicles), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Even if switching characteristics of the heated oxygen sensor 1 are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 3. This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. Under normal conditions the heated oxygen sensor 3 is not used for engine control operation.
More InformationNeed more information on how to fix the P0166 code?
Get Access to Factory Service Manuals