Heated Oxygen Sensor (HO2S)

HO2S is a heat-type sensor which measures oxygen content of exhaust gases. PCM uses data from HO2S to determine air/fuel mixture. Sensors are positioned in exhaust system, ahead of the left and right catalytic converters.

Fuel/air mixture is regulated separately for right and left cylinder banks. Each cylinder bank has its own oxygen sensor and catalytic converter. Using 2 HO2S allows PCM to monitor oxygen content in each cylinder bank individually.

The PCM regulates the amount of fuel injected per cylinder bank based on voltage signals received from the respective oxygen sensors.