Oxygen Sensor: Testing and Inspection

1997 Lexus ES 300 V6-3.0L (1MZ-FE)SECTION Testing and Inspection

HEATED OXYGEN SENSORS INSPECTION

1. Inspect heater resistance of heated oxygen sensors.
(Bank 1 Sensor 1, Bank 2 Sensor 1)
(a) Disconnect the oxygen sensor connector.

Bank 1 Sensor 1:




Bank 2 Sensor 1:





(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.

Torque: 44 N.m (440 kgf.cm, 31 ft.lbf)

(c) Reconnect the oxygen sensor connector.

2. Inspect heater resistance of heated oxygen sensor.
(Bank 1 Sensor 2)
(a) Remove the driver's seat.
(b) Take out the floor carpet.
(c) Disconnect the oxygen sensor connector.





(d) 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.

Torque: 44 N.m (440 kgf.cm, 31 ft.lbf)

(e) Reconnect the oxygen sensor connector.
(f) Reinstall the floor carpet.
(g) Reinstall the driver's seat.

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.