Ford 2002 F650 Owner's Manual page 232

General Maintenance Information
Emissions control system(s) laws
Federal law prohibits vehicle manufacturers, dealers and other persons
engaged in the business of repairing, servicing, selling, leasing or trading
motor vehicles, as well as fleet operators from knowingly removing or
rendering an emissions control device or system inoperative. Further,
modifications of the emissions control system(s) could create liability on
the part of individual owners under the laws of some states. In Canada,
modification of the emissions control system could create liability under
applicable Federal or Provincial laws.
NOISE EMISSIONS WARRANTY, PROHIBITED TAMPERING ACTS
AND MAINTENANCE
On January 1, 1978, Federal regulations became effective governing the
noise emissions on trucks over 4 535 kgs. (10 000 lbs.) GVWR. The
following statements concerning prohibited tampering acts and
maintenance and the noise warranty are found in the Warranty Guide,
and are applicable to completed trucks.
Tampering with noise control system prohibited
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 following
acts listed:
Vehicle System
Acoustical Shielding
Engine
232
Acts
Removal of noise shields, hood blanket,
tunnel liner or acoustical absorptive
material.
Removal or rendering inoperative the
engine speed governor so as to allow
engine speed to exceed manufacturer
specifications. Removal of engine mounted
noise shield or oil pan enclosure.