MUFFLER TONE QUALITY (DIAG./ INSTALL RETURNED MUFFLER)

SUBJECT: L35 MUFFLER TONE QUALITY - DIAGNOSE/INSTALL RETUNED MUFFLER

MODELS/YEARS: 1992 BRAVADA WITH 4.3L (VIN W) ENGINE

Some 1992 Bravadas with the 4.3L (VIN W) CPI engine built before vehicle number N2710107 may exhibit a louder than normal exhaust noise. A retuned muffler, P/N 12541384 and clamp P/N 15595048 will reduce the amount of audible noise. These parts are currently available from GMSPO.

Removing Exhaust Parts

CAUTION:

Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.

Using a penetrating oil on the threads of U-bolts can assist in the removal of the exhaust components.

Installing Exhaust Parts

When installing a new muffler and tailpipe, on any model, check for proper alignment. Rattles and noise vibrations in the exhaust system are usually caused by a misalignment of parts. When aligning the system, leave all bolts or nuts loose until all parts are properly aligned, then tighten, working from the front to rear. Exhaust system hangers, hanger brackets, and clamps which are damaged should be replaced to maintain exhaust system alignment. Refer to the service manual section 6F Exhaust System for addi- tional information.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.