LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Hummer >> 2003 >> H2 >> Repair and Diagnosis >> Engine Mechanical >> Engine Exhaust >> Repair Instructions >> Catalytic Converter Replacement (Left Hand) >> Installation Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Installation Procedure

    Fig 1: Exhaust Manifold Pipe
    GM863015Courtesy of GENERAL MOTORS CORP.
  1. Install a new exhaust manifold pipe seal to the exhaust manifold pipe.
  2. Install the exhaust manifold pipe.
  3. Replace exhaust pipe clamp if necessary.
    4. Fig 2: Exhaust Manifold Pipe Nuts
    GM664826Courtesy of GENERAL MOTORS CORP.
    NOTE: Refer to FASTENER NOTICE .
  4. Install the exhaust manifold pipe nuts.

    Tighten:  Tighten the nuts to 50 N.m (39 lb ft).

  5. Tighten the pipe clamp nut.

    Tighten:  Tighten the pipe clamp nut to 40 N.m (29 lb ft).

    6. Fig 3: View Of O2 Sensor, Connector, Harness And Retainers
    GM664781Courtesy of GENERAL MOTORS CORP.
  6. If the exhaust manifold pipe was replaced perform the following:
    1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.
    2. Install the old oxygen sensors.

      Tighten:  Tighten the oxygen sensors to 42 N.m (31 lb ft).

  7. If the exhaust manifold pipe was not replaced perform the following:
    1. Connect the oxygen sensor electrical connectors.
    2. Connect the CPA retainers.
  8. Install the catalytic converter guard. Refer to CATALYTIC CONVERTER GUARD REPLACEMENT .
  9. Lower the vehicle.
scientia non olet · About LEMON Manuals