GMC Sierra Owners Manual
Noise Control System
The following information relates to compliance with federal noise emission standards for vehicles with a Gross Vehicle Weight Rating (GVWR) of more than 4 536 kg (10,000 lbs). The noise control system warranty is given in your warranty booklet.
These standards apply only to vehicles sold in the United States.
Federal law prohibits the following acts or the causing thereof:
1. The removal or rendering inoperative by any person, other than for purposes of maintenance, repair or replacement, of any device or element of design incorporated into any new vehicle for the purpose of noise control, prior to its sale or delivery to the ultimate purchaser or while it is in use; or 2. The use of the vehicle after such device or element of design has been removed or rendered inoperative by any person.
Among those acts presumed to constitute tampering are the acts listed below.
Removal of the noise shields or any underhood insulation.
Removal or rendering engine speed governor, if the vehicle has one, inoperative so as to allow engine speed to exceed manufacturer specifications.
Fan and Drive:
• Removal of fan clutch, if the vehicle has one, or rendering clutch inoperative.
• Removal of the fan shroud, if the vehicle has one.
• Removal of the air cleaner silencer.
• Modification of the air cleaner.
• Removal of the muffler and/or resonator.
• Removal of the exhaust pipes and exhaust pipe clamps.