METALLIC BUZZ OR RATTLE NOISE INSTALL CLAMP/REPOSITION PIPE

SUBJECT: METALLIC BUZZ OR RATTLE NOISE (INSTALL CLAMP/REPOSITION A.I.R. PIPE)

VEHICLES AFFECTED: 1991-92 CHEVROLET CAMARO, PONTIAC FIREBIRD WITH ENGINE VIN CODE F OR 8 AND DUAL CATALYTIC CONVERTER EXHAUST

CONDITION:

--------- Some 1991-92 F-cars with either a 5.0L or a 5.7 V-8 engines (Vin Code F or 8) and dual catalytic converter exhaust system, may exhibit a metallic buzz or rattle that is most apparent during low speed/ low load type operations.

CAUSE:

----- The two causes indicated below may result in a metallic buzz/ rattle noise:

Cause 1: Intermittent contact between the exhaust pipes just forward of the catalytic converter.

Cause 2: Air injector reactor (A.I.R.) pipe in contact with the toe pan to the front of the dash trim flange.

CORRECTION:

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Correction 1: Install clamp, P/N 10041052, to the inboard exhaust pipe just rearward of the exhaust pipe to the catalytic converter extension pipe. Weld as illustrated in Figure 1.

Correction 2: Reposition A.I.R. pipe to insure clearance of approximately 25 mm (1 inch) between the pipe and trim flange (reference Figure 2).

For vehicles repaired under warranty claim: .3 hr.

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.