Technical Definition:

O2 Circuit No Activity Detected (Bank 2, Sensor 1)

Technical Description:

The oxygen sensors are critical to the engine running properly. It basically informs the PCM (Powertrain Control Module) of oxygen content of the exhaust. The PCM then uses this information to regulate fuel into the engine and maintain proper air:fuel ratio. It is a four wire sensor, with the PCM providing a reference/signal voltage of about half a volt (0.5v) to the sensor. It usually provides a ground also

Possible Causes:

• Faulty bank 2,1 Oxygen sensor
• Holes in exhaust near oxygen sensor
• Short to voltage or ground on signal circuit
• Open or high resistance in signal circuit
• Wiring harness chafing/rubbing on exhaust components
• Water/oil intrusion at O2 sensor connector
• Broken lock or loose terminals on O2 sensor connector
• Oil/coolant fouled oxygen sensor

Possible Symptoms:

• MIL (Malfunction Indicator Lamp) illumination
• Other codes indicating rich or lean condition may be present
• Poor idle, won’t idle
• Misfire at idle or at highway speed
• Engine may blow black smoke at tailpipe
• Fuel economy may decrease
• May start and stall

O2 Sensor Circuit No Activity Detected Bank 2 Sensor 1

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Front Heated Oxygen Sensor Bank 2
– Front Heated Oxygen Sensor Bank 2 harness is open or shorted
– Front Heated Oxygen Sensor Bank 2 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