Technical Definition:

O2 Circuit Low Voltage (Bank 1, Sensor 2)

Technical Description:

Possible Causes:

• Faulty o2 sensor Exhaust leak near the rear sensor
• Plugged catalyst
• Short to voltage on O2 signal circuit
• High resistance or open on O2 signal circuit
• Engine running very rich or lean
• Engine misfire condition
• Fuel pressure very high or low – fuel pump or pressure regulator

Possible Symptoms:

O2 Sensor Circuit Low Voltage Bank 1 Sensor 2

Possible Solutions:

• Replace faulty sensor
• Repair exhaust leak near the rear sensor
• Check for restriction in catalyst and replace as necessary
• Repair short, open, or high resistance on o2 signal circuit

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Rear Heated Oxygen Sensor Bank 1
– Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
– Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
– Inappropriate fuel pressure
– Faulty fuel injectors
– Intake air leaks may be faulty
– Exhaust gas leaks

Specific Makes:

– High Fuel Consumption
– Excessive Smoke from Exhaust