Sentra GXE L4-1.8L (QG18DE) (2000)
Oxygen Sensor: Description and Operation
Heated Oxygen Sensor 1 (Front)
COMPONENT DESCRIPTION
The heated oxygen sensor 1 (front) is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air.
The heated oxygen sensor 1 (front) has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1 V in richer
conditions to 0 V in leaner conditions. The heated oxygen sensor 1 (front) signal is sent to the PCM. The PCM adjusts the injection pulse duration to
achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1 V to 0 V.
Heated Oxygen Sensor 1 Heater (Front)
SYSTEM DESCRIPTION
The PCM performs ON/OFF control of the heated oxygen sensor 1 heater (front) corresponding to the engine operating condition.
Heated Oxygen Sensor 2 (Rear)