GM Service Manual Online
For 1990-2009 cars only

Exhaust System Alignment LY7 and L98 Engines

Notice: Refer to Exhaust System Inspection Notice in the Preface section.

Notice: Refer to Exhaust Service Caution in the Preface section.

Important: This procedure is only to be performed if the exhaust is incorrectly aligned or is not clear of all other components or chassis.

Important: Make sure all exhaust retaining nuts and bolts are loose before conducting this procedure.

Important: The L98 exhaust is pictured but flange bolts are in the same location on LY7.


    Object Number: 1996247  Size: SF
  1. Initially tighten catalytic converter to exhaust manifold retaining nuts (1).
  2. Tighten
    Tighten the nuts to 20 N·m (15 lb ft).

  3. Tighten catalytic converter to exhaust manifold retaining nuts (1).
  4. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).

  5. Tighten exhaust crossover pipe to catalytic converter retaining nuts (2).
  6. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

  7. Tighten muffler to exhaust crossover pipe retaining bolts (3).
  8. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).

Exhaust System Alignment LEO and LW2 Engines

Notice: Refer to Exhaust System Inspection Notice in the Preface section.

Caution: Refer to Exhaust Service Caution in the Preface section.

Important: This procedure is only to be performed if the exhaust is incorrectly aligned or is not clear of all other components or chassis.

Important: Make sure all exhaust retaining nuts and bolts are loose before conducting this procedure.


    Object Number: 1996246  Size: SF
  1. Initially tighten catalytic converter to exhaust manifold retaining nuts (1).
  2. Tighten
    Tighten the nuts to 20 N·m (15 lb ft).

  3. Tighten catalytic converter to exhaust manifold retaining nuts (1).
  4. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).

  5. Tighten exhaust crossover pipe to catalytic converter retaining nuts (2).
  6. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

  7. Tighten muffler to exhaust crossover pipe retaining bolts (3).
  8. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).