O2 sensor Visual Inspection
IG KEY "OFF", ENGINE "OFF".
Disconnect O2 sensor connector.
Perform visual inspection for each checking point as follows.
a. Check corrosion inside of O2 sensor terminal.
b. Check damaged coverring and open in component wiring.
c. Check connecting torque(poor connection) of O2 sensor component.
d. Disconnect O2 sensor and check deformation, clogging, melting of O2 detecting prove.
Secification : Everyting OK
Is any problem of O2 sensor detected?
YES
Replace O2 sensor and go to "Verification of Vehicle Repair".
NO
Refer to "NOTE" as follows.
In diesel engine, ultra lean combustion generates at normal operating condition. Therefore, O2 sensor signal change in accordance with engine acceleration and various loading condition rarely happens, unlikely to linear O2 sensor of gasoline engine. Moreover, pumping current is not measurable with normal measuring device(ampere meter) because maximum value is 3mA. If DTC code is recorded continuously eventhough circuit inspection is correctly performed and no problem at visual inspection of component is detected, replace O2 sensor.