Emissions Controls - Honda 1994 Accord Wagon Reference Owner's Manual

The burning of gasoline in your
car's engine produces several by-
products. 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 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 120.
* In Canada, Honda vehicles
comply with the Canadian Motor
Vehicle Safety Standards (CMVSS)
for Emissions valid at the time
they are manufactured.

Emissions Controls

Crankcase Emissions
Control System
Your car has a Positive Crankcase
Ventilation (PCV) System. This
keeps gasses that build up in the
engine's crankcase from going
into the atmosphere. The PCV
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 fuel 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.
Technical Information