P0166 Audi O2 Sensor Circuit No Activity Detected Bank 2 Sensor 3
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
– Heated Oxygen Sensor Bank 2 Sensor 3 harness is open or shorted
– Heated Oxygen Sensor Bank 2 Sensor 3 circuit poor electrical connection
Tech description
Replacing the O2 Sensor 3 usually takes care of the problem
What about the obd code?
Current amperage in the rear heated oxygen sensor heater circuit has no activity.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– High Fuel Consumption
– Excessive Smoke from Exhaust
– High Fuel Consumption
– Excessive Smoke from Exhaust
P0166 Audi Description
The 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.
P0166 Audi Information for specific makes
P0166 Audi HONDA
Audi Vehicle:Audi A1,Audi A3,Audi A1,Audi A3,Audi A1,Audi A3,Audi A4,Audi A5,Audi Q3,Audi A5,Audi Q5,Audi A3,Audi A4,Audi A5,Audi TT,Audi Q3,Audi Q5,Audi S3,Audi TTS,Audi RS 3,Audi TT RS,Audi A7,Audi Q7,Audi A8,Audi A6,Audi S4,Audi S5,Audi Q5,Audi S6,Audi S8,Audi S5,Audi A8,Audi R8 V8,Audi RS 5,Audi S6,Audi R8 V10,Audi R8 GT,Audi A8L