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Home >> Toyota >> 2003 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 168 (Engine Control System Self Diagnostics (1GR-FE)) >> Diagnostic Tests >> DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1) & DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) >> Confirmation Engine Racing Pattern
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Confirmation Engine Racing Pattern

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

Use this pattern procedure to monitor oxygen sensor (B1 & 2, S2) waveform to determine sensor switching frequency, which is a useful tool in determining catalyst condition (deterioration). See Figure.

  1. Connect hand-held tester to Data Link Connector No. 3 (DLC3) at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester on.
  2. Start engine and warm it up with all the accessories switched OFF until the water temperature is stable.
  3. Race the engine at 2500-3000 RPM for about 3 minutes.
  4. When racing the engine at 3000 RPM for 2 seconds and 2000 RPM for 2 seconds, alternately check the waveform of the oxygen sensor (B1 & 2, S2). See Figure.
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