GMC 2003 Savana Van Owner's Manual page 296

Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:
0
Removal of the noise shields or any underhood
insulation.
Engine:
Removal or rendering engine speed governor (if
equipped) inoperative so as to allow engine
speed to exceed manufacturer specifications.
Fan and Drive:
Removal of fan clutch (if equipped) or rendering
0
Removal of the fan shroud (if equipped).
clutch inoperative.
Air Intake:
0
Removal of the air cleaner silencer.
0
Modification of the air cleaner.
Exhaust:
Removal of the muffler and/or resonator.
0
Removal of the exhaust pipes and exhaust pipe
clamps.
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