Chevrolet 2010 Express Owner's Manual page 322

Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:
•
Removal of the noise shields or any underhood
insulation.
Engine:
•
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.
6-52
Air Intake:
•
Removal of the air cleaner silencer.
•
Modification of the air cleaner.
Exhaust:
•
Removal of the muffler and/or resonator.
•
Removal of the exhaust pipes and exhaust pipe
clamps.
Fuel Operated Heater (FOH) — Diesel
Engine:
•
Removal of the muffler.