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Home >> Chevrolet >> 2001 >> Cutaway 8.1 G >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 8.1L >> Inspection/Maintenance Procedures >> Inspection/Maintenance Catalyst System Set Procedure >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform inspection/maintenance system check. See INSPECTION/MAINTENANCE SYSTEM CHECK . After performing inspection/maintenance system check, go to next step.
    2. WARNING: Road test vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
  2. Ensure vehicle meets the specific conditions before performing procedure. See CONDITIONS FOR RUNNING . Turn off all accessories (e.g., A/C, blower fan, etc.). Start engine and allow to idle for 2 minutes. Accelerate vehicle at part throttle to 55 MPH and maintain speed for 5 minutes. Decelerate to a complete stop. Operate engine at idle for 2 minutes while service brake is depressed, A/T in Drive or M/T in Neutral with clutch pedal depressed. Using scan tool, observe I/M SYSTEM STATUS display. If catalyst system status updates to YES, go to step  5. If catalyst system status does not update to YES, go to next step.
  3. Using scan tool, observe DTC INFO. If any DTCs are set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, go to next step.
  4. Using scan tool, observe the NOT RAN SINCE CODE CLEARED display to determine if DTCs P0420 or P0430 have run. Determine which of the DTCs required for a YES status that have not run. Enter DTC in SPECIFIC DTC menu on scan tool. Operate vehicle within conditions under CODE ENABLE CRITERIA for the specific DTC to run. Repeat procedure until scan tool indicates that diagnostic test has run. Repeat this step for any additional required DTCs that have not run. Using scan tool, observe I/M SYSTEM STATUS display. If status updates to YES, go next step. If status does not update to YES, see DIAGNOSTIC AIDS .
  5. Using scan tool, observe emission related DTC portion of I/M SYSTEM STATUS display. If scan tool indicates any emission related DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.
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