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Emissions Controls
The burning of gasoline in your
vehicle’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. Con-
trolling the production of NOx, CO,
and HC is important to the environ-
ment. Under certain conditions of
sunlight and climate, NOx and HC
react to form photochemical ‘‘smog.’’
Carbon monoxide does not contri-
bute to smog creation, but it is a
poisonous gas.
The Clean Air Act
intake manifold. They are then
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.
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.
＊ In Canada, Honda vehicles comply
with the Canadian emission
requirements, as specified in an
agreement with Environment
Canada, at the time they are
manufactured.
Onboard Refueling Vapor
Recovery
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.
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
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Emissions Controls
Exhaust Emissions Controls
The exhaust emissions controls
include three systems: PGM-FI,
ignition timing control, and three
way catalytic converter. These three
systems work together to control the
engine’s combustion and minimize
the amount of HC, CO, and NOx that
comes out the tailpipe. The exhaust
emissions control systems are
separate from the crankcase and
evaporative emissions control
systems.
PGM-FI System
The PGM-FI system uses sequential
multiport fuel injection.
Three Way Catalytic Converter
The three way catalytic converter is
in the exhaust system. Through
chemical reactions, it converts HC,
CO, and NOx in the engine’s exhaust
It has three subsystems: air intake,
engine control, and fuel control. The
powertrain control module (PCM)
uses various sensors to determine
how much air is going into the
engine. It then controls how much
fuel to inject under all operating
conditions.
2
to carbon dioxide (CO ), nitrogen
2
(N ), and water vapor.
Replacement Parts
The emissions control systems are
designed and certified to work to-
gether in reducing emissions to
levels that comply with the Clean Air
Act. To make sure the emissions
remain low, you should use only new
Honda replacement parts or their
equivalent for repairs. Using lower
quality parts may increase the
emissions from your vehicle.
Ignition Timing Control System
This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
The emissions control systems are
covered by warranties separate from
the rest of your vehicle. Read your
warranty manual for more informa-
tion.
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2024 Honda CR-V Owner's Manual
2023 Honda CR-V Owner's Manual
2021 Honda CR-V Owner's Manual
2018 Honda CR-V Owner's Manual
2015 Honda CR-V Owner's Manual
