Table of Contents > 8. Technical Information > Emissions Controls

2010 Honda CR-V Owner's Manual ➜ Emissions Controls

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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  
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  
Onboard Refueling Vapor  
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  
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  
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  
to carbon dioxide (CO ), nitrogen  
(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-