HONDA 2003 Civic Coupe - Owner's Manual - Manual (Page 298)

The United States Clean Air Act
sets standards for automobile
emissions. It also requires that
automobile manufacturers explain to
owners how their emissions controls
work and what to do to maintain
them. This section summarizes how
the emissions controls work.
Scheduled maintenance is on page
.
The burning of gasoline in your car’s
engine produces several byproducts.
Some of these are carbon monoxide
(CO), oxides of nitrogen (NOx) and
hydrocarbons (HC). Gasoline
evaporating from the tank also
produces hydrocarbons. Controlling
the production of NOx, CO, and HC
is important to the environment.
Under certain conditions of sunlight
and climate, NOx and HC react to
form photochemical ‘‘smog.’’ Carbon
monoxide does not contribute to
smog creation, but it is a poisonous
gas.
In Canada, Honda vehicles comply
with the Canadian emission
requirements, as specified in an
agreement with Environment
Canada, at the time they are
manufactured.
Your car has a Positive Crankcase
Ventilation System. This keeps
gasses that build up in the engine’s
crankcase from going into the
atmosphere. The Positive Crankcase
Ventilation valve routes them from
the crankcase back to the intake
manifold. They are then drawn into
the engine and burned.
As gasoline evaporates in the fuel
tank, an evaporative emissions
control canister filled with charcoal
adsorbs the vapor. It is stored in this
canister while the engine is off. After
the engine is started and warmed up,
the vapor is drawn into the engine
and burned during driving.
194
The Clean Air Act
Crankcase Emissions Control
System
Evaporative Emissions Control
System
Emissions Controls
Technical Inf ormation 295
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