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Home >> Hummer >> 2007 >> H3 Automatic >> Repair and Diagnosis >> Engine Mechanical >> Engine Exhaust >> Repair Instructions >> Catalytic Converter Replacement >> Installation Procedure
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Installation Procedure

    Fig 1: View Of Exhaust Manifold Seal
    GM1313620Courtesy of GENERAL MOTORS CORP.
  1. Install a NEW seal to the exhaust manifold flange.
    2. Fig 2: View Of Catalytic Converter
    GM1313621Courtesy of GENERAL MOTORS CORP.
    NOTE: Refer to Exhaust System Inspection Notice .
  2. Install the catalytic converter to the exhaust manifold.
  3. Install the nuts attaching the catalytic converter to the exhaust manifold. Do not tighten at this time.
    4. Fig 3: View Of Nuts Securing Muffler To Catalytic Converter
    GM1560112Courtesy of GENERAL MOTORS CORP.
  4. Align the catalytic converter with the studs located in the muffler.
    5. NOTE: Refer to Fastener Notice .
  5. Install the nuts securing the muffler to the catalytic converter. Tighten the nuts by hand until each contacts the metal flange.

    Tighten:  Tighten the nuts to 45 N.m (33 lb ft).

  6. Tighten the catalytic converter nuts previously installed in step 3.

    Tighten:  Tighten the nuts to 50 N.m (37 lb ft).

  7. Install the HO2S if previously removed. Refer to Heated Oxygen Sensor 2 Replacement .
    8. Fig 4: View Of Exhaust Hanger And Exhaust Muffler Hanger Rod
    GM1560120Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Do not use oil base lubricants.
  8. Apply a soapy solution to the following in order to ease the installation of the hanger (2):
    • The inner diameter of the exhaust muffler hanger (2)
    • The exhaust muffler hanger rod (3)
    9. Fig 5: View Of HO2S Electrical Connector
    GM1363915Courtesy of GENERAL MOTORS CORP.
  9. Connect the HO2S at the pigtail (3).
  10. Install the right torsion bar. Refer to Torsion Bar Replacement .
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