Acura 2009 MDX - Owner's Manual - Manual (Page 464)

The burning of gasoline in your
vehicle'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 Clean Air Act
The United States Clean Air Act
ꭧ
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
390 .
ꭧ In Canada, Acura vehicles comply
with the Canadian emission
requirements, as specified in an
agreement with Environment
Canada, at the time they are
manufactured.
Crankcase Emissions Control
System
Your vehicle 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.
Evaporative Emissions Control
System
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.
Emissions Controls
460
08/06/06 16:58:07 09 ACURA MDX MMC North America Owner's M 50 31STX620 enu
2009 MDX
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