Quest Minivan SE V6-3.3L (VG33E) (1999)
Oxygen Sensor: Description and Operation
Rear Heated Oxygen Sensor
COMPONENT DESCRIPTION
The rear heated oxygen sensor, after three way catalyst, monitor the oxygen level in the exhaust gas on each bank.
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 1 V in richer conditions to 0 V in leaner conditions.
Under normal conditions the rear heated oxygen sensor is not uses for engine control operation.
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the rear heated oxygen sensor heater corresponding to the engine speed.