Acura 2004 TSX - Owner's Manual - Manual (Page 345)

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.
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
.
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.
The Onboard Refueling Vapor
Recovery (ORVR) system captures
the fuel vapors during refueling. The
vapors are adsorbed in a canister
filled with activated carbon. While
driving, the fuel vapors are drawn
into the engine and burned off.
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.
In Canada, Acura vehicles comply
with the Canadian emission
requirements, as specified in an
agreement with Environment
Canada, at the time they are
manufactured.
232
The Clean Air Act
Crankcase Emissions Control
System
Onboard Ref ueling Vapor
Recovery
Evaporative Emissions Control
System
Emissions Controls
Technical Inf ormation 342
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