Segway SGW500F-A7 Owner's Manual page 173

EMISSION CONTROL SYSTEM
SOURCE OF EXHAUST EMISSIONS
The combustion process produces carbon monoxide(CO), oxides
of nitrogen(NOx)and hydrocarbons(HC). Control of hydrocarbons
and oxides of nitrogen is very important because, under certain
conditions, they react to form photochemical smog when
subjected to sunlight. Carbon monoxide does not react in the
same way, but it is toxic.
EXHAUST EMISSION CONTROL SYSTEM
The exhaust emission control system includes a PGM-F system
and oxygen sensor.
No adjustments to this system should be made although periodic
inspection of the components is recommended.
The exhaust emission control system is separate from the
crankcase emission control system.
CRANKCASE EMISSION CONTROL SYSTEM
The engine is equipped with a closed crankcase system to prevent
discharging crankcase emissions into the atmosphere. Blow-
by gas is returned to the combustion chamber through the air
cleaner.
NOISE CONTROL SYSTEM
Do not modify the engine,air intake or exhaust components, in
order to meet local noise level requirements.
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