Circuit/System Testing

2008 Chevrolet Chevy Express G3500, Van Passenger ExtendedSECTION Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
IMPORTANT: Perform the Repair Verification after completing the Circuit/System Testing.
  1. Inspect the DOC for any of the following abnormal conditions:
    • Physical damage or alterations
    • Internal rattles caused by a damaged catalyst substrate
    • Internal restrictions-Refer to Restricted Exhaust .
    • If a condition is found, replace the DOC.
  2. Inspect the exhaust system for the following conditions:
    • Restrictions-Refer to Restricted Exhaust .
    • Exhaust leaks before DPF
    • Physical damage or alterations
    • If a condition is found, repair the exhaust system as necessary.
  3. Inspect for the following conditions, which may cause a DOC to degrade:
    • If a condition is found, repair as necessary, then replace the DOC.
  4. If all inspections and tests are normal, replace the DOC.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.