Technical Definition:

O2 Circuit Slow Response (Bank 1, Sensor 2)

Technical Description:

The involves the rear oxygen sensor on the driver’s side. This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use.

Possible Causes:

• The oxygen sensor is faulty
• The wiring to the sensor is broken / frayed
• There is an exhaust leak

Possible Symptoms:

O2 Sensor Circuit Slow Response Bank 1 Sensor 2

Possible Solutions:

• Check and fix any exhaust leaks
• Check for wiring problems (shorted, frayed wires)
• Check the frequency and amplitude of the oxygen sensor (advanced)
• Check for a deteriorating / contaminated oxygen sensor, replace if necessary
• Check for inlet air leaks
• Check the MAF sensor for proper operation

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