Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSTOYOTA2002HIGHLANDER 4WD L4-2.4L (2AZ-FE)REPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSSENSORS AND SWITCHES - COMPUTERS AND CONTROL SYSTEMSOXYGEN SENSORTESTING AND INSPECTION
2002 Toyota Highlander 4WD L4-2.4L (2AZ-FE)
Oxygen Sensor: Testing and Inspection
2002 Toyota Highlander 4WD L4-2.4L (2AZ-FE)SECTION Testing and Inspection
INSPECT HEATER RESISTANCE OF A/F SENSOR (No. 1, No. 4 Cylinder side)
a. Disconnect the A/F sensor connector.
b. Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance:
1.8 - 3.4 (Ohm) at 20 °C (68 °F)
5.0 - 7.5 (Ohm) at 500 °C (932 °F)
If the resistance is not as specified, replace the sensor.
c. Reconnect the A/F sensor connector.
INSPECT HEATER RESISTANCE OF A/F SENSOR (No. 2, No. 3 Cylinder side)
a. Disconnect the A/F sensor connector.
b. Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance:
1.8 - 3.4 (Ohm) at 20 °C (68 °F)
5.0 - 7.5 (Ohm) at 500 °C (932 °F)
It the resistance is not as specified, replace the sensor.
c. Reconnect the A/F sensor connector.
INSPECT HEATER RESISTANCE OF OXYGEN SENSORS
a. Disconnect the oxygen sensor connector.
b. Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance: 11 - 16 (Ohm) at 20°C (68°F)
If the resistance is not as specified, replace the sensor.
c. Reconnect the oxygen sensor connector.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.