Technical Definition:

O2 Circuit High Voltage (Bank 1, Sensor 3)

Technical Description:

The catalytic converter is used to lower harmful emissions. To ensure proper operation, there is an O2 sensor located behind the catalyst that monitors the oxygen content of the exhaust after the cat. The PCM (Powertrain Control Module) then compares the post-cat reading to the pre-cat readings to determine if the catalyst is working properly.

Possible Causes:

• ad o2 sensor (Bank 1 Sensor 3)
• Wiring in contact with exhaust components
• Engine running rich (If other codes are present)
• Holes in exhaust near Bank 1 Sensor 3
• Short to voltage on signal circuit
• Bad PCM

Possible Symptoms:

• MIL (Malfunction Indicator Lamp) on
• Engine loses power and misses intermittently
• May exhibit loss of fuel efficiency

O2 Sensor Circuit High Voltage Bank 1 Sensor 3

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Heated Oxygen Sensor Bank 1 Sensor 3
– Heated Oxygen Sensor Bank 1 Sensor 3 harness is open or shorted
– Heated Oxygen Sensor Bank 1 Sensor 3 circuit poor electrical connection

Specific Makes:

– High Fuel Consumption
– Excessive Smoke from Exhaust