Heated Oxygen Sensor (HO2S)

Heated Oxygen Sensor 1
The heated oxygen sensor 1 (HO2 sensor 1) is a linear characteristic type sensor, fitted forward of the exhaust system's catalytic converter. The sensor is used by the ECM as a primary sensor to measure oxygen content within the exhaust system. The sensor is used in conjunction with the ECM to provide closed loop fuelling control.

Heated Oxygen Sensor 2
The heated oxygen sensor 2 (HO2 sensor 2) is a non-linear characteristic type sensor fitted to the exhaust system's catalytic converter, and is used by the ECM as a secondary sensor to measure oxygen content within the exhaust system. Used in conjunction with the ECM and the HO2 sensor 1, the HO2 sensor 2 aids closed-loop fuelling control. It is also used to monitor catalyst efficiency.