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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 >> Overall Function Check >> At Models Except ULEV >> With GST
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With GST

  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. Open engine hood.
  6. Set voltmeter probe between ECM terminal 74 and ground.
  7. Keep engine speed at 2, 500 RPM constant under no load.
  8. Make sure that the voltage does not vary for more than 5 seconds.

    If the voltage fluctuation cycle takes less than 5 seconds, GO TO "DIAGNOSTIC PROCEDURE ".

    • 1 cycle: 0.6 - 1.0 V --> 0 - 0.3 V --> 0.6 -1.0 V
    9. Fig 1: Setting Voltmeter Probes Between ECM Terminal 74 & Ground
    G00777916Courtesy of NISSAN MOTOR CO., U.S.A.
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