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Home >> Toyota >> 2004 >> Avalon XLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Diagnostics >> DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1) >> Confirmation Engine Racing Pattern
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Confirmation Engine Racing Pattern

Fig 1: Identifying Confirmation Engine Racing Pattern
G02835858Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. Connect the OBD II scan tool or hand-held tester to the DLC3.
  2. Start engine and warm it up with all the accessories switched OFF until the water temperature is stable.
  3. Race the engine at 2,500 - 3,000 RPM for about 3 min.
  4. When racing the engine at 3,000 RPM for 2 sec. and 2,000 RPM for 2 sec. alternately, check the waveform of the heated oxygen sensor (bank 1 sensor 2).