P0161 CADILLAC - HO2S Heater Performance Bank 2 Sensor 2
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks
- Exhaust gas leaks
When is the code detected?
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible higher than usual fuel consumption
P0161 Cadillac Description
The Powertrain Control Module (PCM) supplies a bias voltage (approximately 450 mV) on the Heated Oxygen Sensor (HO2S) signal high and low circuits. When you turn the ignition to the ON position, battery voltage is supplied to the HO2S heater. As the heater reaches the operating temperature, the HO2S voltage responds by changing from a bias voltage range to the normal operation. Typically, as the HO2S reaches the operating temperature, the HO2S voltage goes from a bias voltage to a voltage below 300 mV. Depending on the exhaust gas content, it is possible for the HO2S voltage to go above 450 mV.