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EnglishTechnical Information -> Emissions Control for your Honda CR-V 2006-2010
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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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Three Way Catalytic Converter
The three way catalytic converter
contains precious metals that serve
as catalysts, promoting chemical
reactions to convert the exhaust
gasses without affecting the metals.
The catalytic converter is referred to
as a three-way catalyst, since it acts
on HC, CO, and NOx. A replacement
unit must be an original Honda part
or its equivalent.
Keep the engine well maintained.
THREE WAY CATALYTIC CONVERTERS
Have your vehicle diagnosed and
repaired if it is misfiring, back-
firing, stalling, or otherwise not
running properly.
The three way catalytic converter
must operate at a high temperature
for the chemical reactions to take
place. It can set on fire any
combustible materials that come
near it. Park your vehicle away from
high grass, dry leaves, or other
flammables.
A defective three way catalytic
converter contributes to air pollution,
and can impair your engine’s per-
formance. Follow these guidelines to
protect your vehicle’s three way
catalytic converter.
Always use unleaded gasoline.
Even a small amount of leaded
gasoline can contaminate the
catalyst metals, making the three
way catalytic converter ineffective.
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Emissions Testing
Testing of Readiness Codes
If you take your vehicle for an
emissions test shortly after the
battery has been disconnected or
gone dead, it may not pass the test.
This is because of certain ‘‘readiness
codes’’ that must be set in the on-
board diagnostics for the emissions
systems. These codes are erased
when the battery is disconnected,
and set again only after several days
of driving under a variety of
If the testing facility determines that
the readiness codes are not set, you
will be requested to return at a later
date to complete the test. If you must
get the vehicle retested within the
next two or three days, you can
condition the vehicle for retesting by
doing the following.
4. Without touching the accelerator
pedal, start the engine, and let it
idle for 20 seconds.
5. Keep the vehicle in Park. Increase
the engine speed to 2,000 rpm, and
hold it there until the temperature
gauge rises to at least 1/4 of the
scale (about 3 minutes).
1. Make sure the gas tank is nearly,
but not completely, full (around
3/4).
6. Without touching the accelerator
pedal, let the engine idle for 20
seconds.
conditions.
2. Make sure the vehicle has been
parked with the engine off for 6
hours or more.
3. Make sure the ambient
temperature is between 40° and
95°F (4° and 35°C).
CONTINUED
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Emissions Testing
7. Select a nearby lightly traveled
major highway where you can
maintain a speed of 50 to 60 mph
(80 to 97 km/h) for at least 20
minutes. Drive on the highway in
D. Do not use the cruise control.
When traffic allows, drive for 90
seconds without moving the
accelerator pedal. (Vehicle speed
may vary slightly; this is okay.) If
you cannot do this for a
8. Then drive in city/suburban
traffic for at least 10 minutes.
When traffic conditions allow, let
the vehicle coast for several
seconds without using the
accelerator pedal or the brake
pedal.
9. Make sure the vehicle has been
parked with the engine off for 30
minutes.
continuous 90 seconds because of
traffic conditions, drive for at least
30 seconds, then repeat it two
more times (for a total of 90
seconds).
If the testing facility determines the
readiness codes are still not set, see
your dealer.
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