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Home >> Buick >> 2004 >> LeSabre Custom, 4T65E/MN3 >> Repair and Diagnosis >> Engine Mechanical >> Engine Exhaust System >> Repair Instructions >> Exhaust System Replacement >> Removal Procedure

Removal Procedure

Servicing of the catalytic converter, resonator or pipe requires the replacement of the exhaust system as a complete one-piece unit.

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement .
  3. Disconnect the heated oxygen sensor at the pigtail.
  4. Remove the heated oxygen sensor if replacement is necessary. Refer to Heated Oxygen Sensor Replacement - Position 2 in Engine Controls - 3.8 L.
  5. Fig 1: View Of Exhaust Pipe To Catalytic Converter
    GM691381Courtesy of GENERAL MOTORS CORP.
  6. Remove the four nuts securing the catalytic converter to the exhaust manifold pipe.
  7. Remove the catalytic converter gasket. Do not reuse the gasket.
  8. Suitably support the exhaust system.
  9. Fig 2: View Of Center Exhaust Hangers & Bolts
    GM691380Courtesy of GENERAL MOTORS CORP.
  10. Remove the two bolts securing the center exhaust hangers to the rear suspension support brackets.
  11. Fig 3: View of Rear Exhaust Hanger Bracket & Exhaust System
    GM693564Courtesy of GENERAL MOTORS CORP.
  12. Remove the bolt securing the rear exhaust hanger bracket to the rear compartment rail.
  13. With the aid of an assistant, lower the exhaust system.
  14. Fig 4: View of Rear Exhaust Hanger Bracket from Rear Exhaust Hanger
    GM693562Courtesy of GENERAL MOTORS CORP.
  15. Remove the nut securing the rear exhaust hanger to the rear exhaust hanger bracket.
  16. Remove the rear exhaust hanger bracket from the rear exhaust hanger.