For 1990-2009 cars

# ENGINE MISS AND OR CODE 33 MAY BE KINKED VACUUM HOSE

ENGINE MISS AND/OR CODE 33

#### VEHICLES AFFECTED: 1988 'N' BODY EQUIPPED WITH ----------------- THE QUAD 4 (LD2) ENGINE

A condition of an engine miss and/or a "Service Engine Soon" light with Code 33 stored in the memory may be caused by a kinked vacuum hose to the MAP sensor on a 1988 Calais equipped with the Quad 4 (LD2) engine. When this condition is present, the engine ignition timing is affected.

This condition can be corrected by inspecting and removing any kinks in the MAP sensor vacuum line prior to performing any additional diagnostics.

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.