HONDA 2005 Civic Sedan - Owner's Manual - Manual (Page 217)

The exhaust emissions controls
include three or four systems: PGM-
FI, ignition timing control, exhaust
gas recirculation (SOHC VTEC
engine only), 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
comes out the tailpipe. The exhaust
emissions control systems are
separate from the crankcase and
evaporative emissions control
systems.
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
then controls how much fuel to inject
under all operating conditions.
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.
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.
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.
This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
2
2
Exhaust Emissions Controls Replacement Parts
PGM-FI System
Three Way Catalytic Converter
Exhaust Gas Recirculation (EGR)
System
Ignition Timing Control System
Emissions Controls
216
Main Menu Table of Contents