Frontier XE King Cab 2WD L4-2.4L (KA24DE) (2000)
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 1 V in richer conditions to 0 V in leaner conditions.
Under normal conditions the rear heated oxygen sensor is not used for engine control operation.
SYSTEM DESCRIPTION
Rear Heated Oxygen Sensor Heater
The ECM performs ON/OFF control of the rear heated oxygen sensor heater corresponding to the engine speed.