MOAN OR CHIRPING NOISE CATALYTIC CONV. CHECK

VEHICLES AFFECTED: 1982-84 Devilles, Fleetwoods and '85 Fleetwood Broughams Equipped With HT4100 Engines ----------------------------------------------

Some 1982-84 Devilles, Fleetwoods and 1985 Fleetwood Broughams equipped with HT4100 engines may exhibit a moan or chirping noise from the A.I.R. system at idle due to the catalytic converter air injection check valve. A malfunctioning check valve can be identified by pinching off the rubber hose which feeds air from the air switch valve to the catalytic converter. If the noise stops when the hose is pinched, replace the catalytic converter air injection check valve with P/N 22048209. The new part should be black with a white dot painted on it.

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.