LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2017 >> QX80 Base, RWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (DTCS) (2 Of 4) >> DTC/Circuit Diagnosis >> DTC P0138, P0158: Ho2S2 >> Component Inspection (Ho2 Sensor 2) >> Diagnostic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Test

  1. INSPECTION START

    Will CONSULT be used?

    Will CONSULT be used?

    YES 

    GO TO STEP 2  .

    NO 

    GO TO STEP 3  .

  2. CHECK HEATED OXYGEN SENSOR 2

    G-20 WITH CONSULT

    1. Start engine and warm it up to the normal operating temperature.
    2. Start engine and keep the engine speed between 3, 500 and 4, 000 rpm for at least 1 minute under no load.
    3. Let engine idle for 1 minute.
    4. Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)/(B2)" as the monitor item with CONSULT.
    5. Check "HO2S2 (B1)/(B2)" at idle speed when adjusting "FUEL INJECTION" to +-25%.
      G05979026Courtesy of NISSAN NORTH AMERICA, INC.

      "HO2S2 (B1)/(B2)" should be above 0.74 V at least once when the "FUEL INJECTION" is +25%. 

      "HO2S2 (B1)/(B2)" should be below 0.18 V at least once when the "FUEL INJECTION" is - 25%. 

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    GO TO STEP  6.

  3. CHECK HEATED OXYGEN SENSOR 2-I

    G-21 WITHOUT CONSULT

    1. Start engine and warm it up to the normal operating temperature.
    2. Turn ignition switch OFF and wait at least 10 seconds.
    3. Start engine and keep the engine speed between 3, 500 and 4, 000 rpm for at least 1 minute under no load.
    4. Let engine idle for 1 minute.
    5. Check the voltage between ECM harness connector terminals under the following conditions.
      ECM Condition Voltage
      + -
      Connector Terminal Connector Terminal
      F92 84
      [HO2S2 (bank 1)]
      F91 43 Revving up to 4, 000 rpm under no load at least 10 times The voltage should be above 0.74 V at least once during this procedure.
      The voltage should be below 0.18 V at least once during this procedure.
      77
      [HO2S2 (bank 2)]

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    GO TO STEP 4  .

  4. CHECK HEATED OXYGEN SENSOR 2-II

    Check the voltage between ECM harness connector terminals under the following conditions.

    ECM Condition Voltage
    + -
    Connector Terminal Connector Terminal
    F92 84
    [HO2S2 (bank 1)]
    F91 43 Keeping engine at idle for 10 minutes The voltage should be above 0.74 V at least once during this procedure.
    The voltage should be below 0.18 V at least once during this procedure.
    77
    [HO2S2 (bank 2)]

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    GO TO STEP 5  .

  5. CHECK HEATED OXYGEN SENSOR 2-III

    Check the voltage between ECM harness connector terminals under the following conditions.

    ECM Condition Voltage
    + -
    Connector Terminal Connector Terminal
    F92 84
    [HO2S2 (bank 1)]
    F91 43 Coasting from 80 km/h (50 MPH) with selector lever in the D position The voltage should be above 0.74 V at least once during this procedure.
    The voltage should be below 0.18 V at least once during this procedure.
    77
    [HO2S2 (bank 2)]

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    GO TO STEP 6  .

  6. REPLACE HEATED OXYGEN SENSOR 2

    Replace malfunctioning heated oxygen sensor 2. Refer to EXPLODED VIEW WITH TORQUE SPECIFICATIONS .

    CAUTION:
    • Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
    • Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor  Thread Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).

    INSPECTION END