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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Qr25DE >> DTC P0420: Three Way Catalyst Function >> Diagnostic Trouble Code (DTC) Confirmation Procedure >> A/T Models Except ULEV >> Testing Condition:
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Testing Condition:

Do not hold engine speed for more than the specified minutes below. 

  1. Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT-II.
  2. Start engine and warm it up to normal operating temperature.
  3. Turn ignition switch OFF and wait at least 10 seconds.
  4. Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1 minute under no load.
  5. Let engine idle for 1 minute.
  6. Make sure that "COOLAN TEMP/S" indicates more than 70°C (158°F).
  7. Open engine hood.
  8. Fig 1: Selecting Data Monitor Mode With Consult-II (A/T Models Except ULEV)
    G00777910Courtesy of NISSAN MOTOR CO., U.S.A.
  9. Select "DTC & SRT CONFIRMATION" then "SRT WORK SUPPORT" mode with CONSULT-II.
  10. Rev engine up to 2, 500 to 3, 500 RPM and hold it for 3 consecutive minutes, then release the accelerator pedal completely.

    If "CMPLT" of "CATALYST" changed to "COMPLT", GO TO STEP  12.

  11. Wait 5 seconds at idle.
    Fig 2: Selecting DTC & SRT Confirmation Then SRT Work Support Mode With Consult-II (A/T Models Except ULEV)
    G00777911Courtesy of NISSAN MOTOR CO., U.S.A.
  12. Rev engine up to 2, 000 to 3, 000 RPM and maintain it until "IMCMP" of "CATALYST" changes to "CMPLT" (it will take approximately 5 minutes).

    If not "CMPLT", stop engine and cool it down to less than 70°C (158°F) and then retest step 1.

    Fig 3: Ensuring CATALYST Changes To CMPLT (A/T Models Except ULEV)
    G00777912Courtesy of NISSAN MOTOR CO., U.S.A.
  13. Select "SELF-DIAG RESULTS" mode with CONSULT-II.
  14. Confirm that the 1st trip DTC is not detected.

    If the 1st trip DTC is detected, GO TO "DIAGNOSTIC PROCEDURE ".

    Fig 4: Selecting SELF-DIAG RESULTS Mode With Consult-II (A/T Models Except ULEV)
    G00777913Courtesy of NISSAN MOTOR CO., U.S.A.