Pathfinder LE 4WD V6-3.3L (VG33E) (1997)
Oxygen Sensor: Description and Operation
Rear Heated Oxygen Sensor
Rear HO2S (Left Bank)
COMPONENT DESCRIPTION
The rear heated oxygen sensor (Rear HO2S), after three way catalyst, monitors the oxygen level in the exhaust gas.
Even it switching characteristics of the front heated oxygen sensor are shifted, the air fuel ratio is controlled to stoichiometric, by the signal from the
rear heated oxygen sensor. This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V
in leaner conditions.
Under normal conditions the rear heated oxygen sensor is not used for engine control operation.
Rear HO2S (Right Bank)
COMPONENT DESCRIPTION
The rear heated oxygen sensor (Rear HO2S), after three way catalyst, monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the front heated oxygen sensor are shifted, the air fuel ratio is controlled to stoichiometric, by the signal from the
rear heated oxygen sensor.
This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions.
Under normal conditions the rear heated oxygen sensor is not used for engine control operation.
Rear HO2S Heater (Right & Left Bank)
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the rear heated oxygen sensor heaters corresponding to the engine speed.
OPERATION
Engine speed rpm / Rear heated oxygen sensor heaters
Above 3,200 / OFF
Below 3,200 / ON