Honda FourTrax Rancher TRX420FA5 2020, Owner'S Manual

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Technical Information 243
Emission Control Systems
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.
Honda Motor Co., Ltd. utilizes various systems to reduce carbon
monoxide, oxides of nitrogen and hydrocarbons.
Exhaust Emission Control System
The exhaust emission control system includes a PGM-FI system and
oxygen sensor.
No adjustment 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.
Evaporative Emission Control System
(USA - 50 States [meets California])
An evaporative emissions control system uses a canister filled with
charcoal to adsorb fuel vapor from the fuel tank while the engine is
off. The vapor is drawn into the engine and burned while driving.
Models sold in and used in California:
An add-on or modified part must be compliant with applicable ARB
evaporative emission control standards. A violation of this
requirement is punishable by civil and/or criminal punishment.
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.
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