Montero 4WD V6-3.5L SOHC (1998)
Oxygen Sensor: Testing and Inspection
California
TROUBLESHOOTING HINTS
Hint 1:
The exhaust gas purification performance will worsen it there is a malfunction of the heated oxygen sensor.
Hint 2:
If the heated oxygen sensor output voltage is outside the standard value even though the results of the checking of the heated oxygen sensor are
normal, the cause is probably a malfunction of a component related to mixture control.
[Examples]:
(1) Malfunction of injector.
(2) Air is drawn into the intake manifold from a leaking gasket, etc.
(3) Malfunction of volume air flow sensor, intake air temperature sensor, barometric pressure sensor or engine coolant temperature sensor.
INSPECTION:
Using Scan Tool
<Heated Oxygen Sensor (front)>
<Heated Oxygen Sensor (rear)>
HARNESS INSPECTION:
STEP 1. Check for continuity between heated oxygen sensor and MFI relay.
-
MFI relay connector: Disconnected
-
Heated oxygen sensor connector: Disconnected
-
Insert the probes of the circuit tester into both ends of the harness.
OK: GO TO STEP 2
NG: Repair the harness. (A, B, C, D1 - E3)