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Home >> Suzuki >> 2002 >> Esteem GL, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 1.6L >> Diagnostic Tests >> DTC P0420: Catalyst System Efficiency Below Threshold >> DTC Confirmation Test
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DTC Confirmation Test

  1. Turn ignition off, connect scan tool and turn ignition on. Using scan tool, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Ensure fuel tank is at least 1/4 full, vehicle is at an altitude of 8000 feet or below, barometric pressure is 75 kPa or more, ambient temperature is 14°F (-10°C) or more, intake air temperature is 158°F (70°C) or less, and engine coolant temperature 158-230°F (70-110°C). Go to, next step.
  2. Drive vehicle at speeds of 35-45 MPH for 8 minutes or more. Using scan tool, check completion status for catalyst monitoring test in READINESS TESTS mode. If scan tool indicates TEST COMPLETED and no DTC are set, DTC confirmation test is complete. If scan tool indicates TEST NOT COMPLETED, go to next step.
  3. Reduce speed to 30-40 MPH for 2 minutes. Ensure short term fuel trim is between -20 and +20 percent. Stop vehicle, leave ignition on and confirm test results. See TEST RESULT CONFIRMATION FLOW  .
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