Civic L4-1.3L Hybrid (2008)
Oxygen Sensor: Description and Operation
Secondary Heated Oxygen Sensor (HO2S)
Secondary Heated Oxygen Sensor (Secondary HO2S)
The secondary HO2S detects the oxygen content in the exhaust gas downstream of the warm up three way catalytic converter (WU-TWC), and sends
signals to the PCM which varies the duration of fuel injection accordingly. To stabilize its output, the sensor has an internal heater. The PCM compares
the HO2S output with the A/F sensor output to determine catalyst efficiency. The secondary HO2S is located on the WU-TWC.
