Frontier 2WD L4-2.5L (QR25DE) (2005)
Oxygen Sensor: Description and Operation
HO2S2 HEATER
Description
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed, amount of intake air and engine coolant
temperature.
OPERATION
HO2S2
Component Description
The heated oxygen sensor 2, after three way catalyst (manifold), monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the A/F sensor 1 are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen
sensor 2.
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 heated oxygen sensor 2 is not used for engine control operation.
A/F SENSOR 1 HEATER
Description