Honda 2008 Accord Owner's Manual page 398

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Exhaust Emissions Controls
The exhaust emissions controls
include three or four systems: PGM-
FI, ignition timing control, exhaust
gas recirculation (V6 models), and
three way catalytic converter. These
three or four systems work together
to control the engine's combustion
and minimize the amount of HC, CO,
and NOx that come 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. It has three
subsystems: air intake, engine
control, and fuel control. The
powertrain control module (PCM) in
automatic transmission vehicles or
the engine control module (ECM) in
manual transmission vehicles uses
various sensors to determine how
much air is going into the engine. It
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then controls how much fuel to inject
under all operating conditions.
Ignition Timing Control System
This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
Exhaust Gas Recirculation (EGR)
System
V6 models
The exhaust gas recirculation (EGR)
system takes some of the exhaust
gas and routes it back into the intake
manifold. Adding exhaust gas to the
air/fuel mixture reduces the amount
of NOx produced when the fuel is
burned.
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
to carbon dioxide (CO ), nitrogen
(N ), and water vapor.
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2008 Accord Sedan
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.
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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Emissions Controls
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