The exhaust emissions controls
include f our systems: PGM-FI,
ignition timing control, exhaust gas
recirculation, and three way catalytic
converter. These f our 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 f rom the crankcase and
evaporative emissions control
systems.
The PGM-FI system uses sequential
multiport f uel injection. It has three
subsystems: air intake, engine
control, and f uel 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. Itthen controls how much f uel to inject
under all operating conditions. The emissions control systems are
designed and certif ied 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 f or repairs. Using lower
qualitypartsmayincreasethe
emissions f rom 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 exhaust gas recirculation (EGR)
system takes some of the exhaust
gas and routes it back into the intake
manif old. Adding exhaust gas to the
air/f uel mixture reduces the amount
of NOx produced when the f uel is
burned. This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
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.
2
2
Emissions Cont rols
Exhaust Emissions Controls Replacement Parts
PGM-FI System
Three Way Catalytic Converter
Exhaust Gas Recirculat ion (EGR)
Syst em
Ignit ion T iming Cont rol Syst em
Technical Inf ormation
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