AN EXHAUST BOOM MAY OCCUR ON 2.5L 1983 CELEBRITY AND CITATION MODELS IN THE 1500 TO 1700 RPM RANGE (30-50 MPH). THE CONDITION IS USUALLY ALLEVIATED BY LOOSENING THE TWO (2) BALL SOCKET BOLTS AT THE CATALYTIC CONVERTER ATTACHMENT, PULL CONVERTER DOWNWARD TO MAKE SURE BALL JOINT IS FREE , THEN RAISE FRONT PIPE AT CONVERTER COMPLETELYUP TO UNDERBODY AND HOLD THERE WHILE TORQUING THE TWO BOLTS TO 20-24 N.M (15-17 FT. LB.). THIS WILL REMOVE EXCESS PRESSURE OR LOADING OF EXHAUST HANGERS. INSPECT THE SYSTEM TO INSURE THAT ADEQUATE CLEARANCE IS MAINTAINED AFTER REPOSITIONING.
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.