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Home >> Lexus >> 2004 >> IS 300 Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 51 (Engine Controls - Self-Diagnostics) >> 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 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect OBD-II scan tool or hand-held tester to DLC3. See Figure.
  2. Start engine and warm it up with all accessories switched off until water temperature becomes stable.
  3. Race engine at 2,500-3,000 RPM for approximately 3 minutes.
  4. Race engine at 3,000 RPM for 2 seconds and 2,000 RPM for 2 seconds alternately and check the waveform of the heated oxygen sensor (bank 1 sensor 2). See Fig 1.
Fig 1: Confirmation Engine Racing Pattern
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