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Home >> Infiniti >> 2003 >> FX45 >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1) Or DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) >> DTC Confirmation Test (Using Generic Scan Tool)
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DTC Confirmation Test (Using Generic Scan Tool)

NOTE: Use the following test to check overall function of 3-way catalyst. During this test, 1st trip DTC may not be confirmed.
CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  1. Turn ignition off and wait at least 10 seconds.
  2. Start engine and keep engine speed between 3500 and 4000 RPM for at least one minute under no load.
  3. Let engine idle for one minute.
  4. Open engine hood. Set voltmeter probes between ECM terminals No. 16 HO2S1 (bank 1) signal, No. 35 HO2S1 (bank 2) signal and engine ground. Also set probes between ECM terminals No. 55 HO2S2 (bank 1) signal, No. 74 HO2S2 (bank 2) signal and engine ground.
  5. Keep engine speed at 2000 RPM constant under no load.
  6. If switching frequency of rear HO2S is less than 75 percent of front HO2S switching frequency, catalyst is operating properly. If switching frequency of rear HO2S is not less than 75 percent of front HO2S switching frequency, go to DIAGNOSTIC PROCEDURE  . If front HO2S does not switch more than 5 times within 10 seconds, diagnose and repair front HO2S. See DTC P0133 OR P0153  .
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