Acura 2004 NSX Owner's Manual page 211

Main Menu Table of Contents
Emissions Controls
Exhaust Emissions Controls
The exhaust emissions controls
include four systems: PGM-FI,
Ignition Timing Control, Exhaust
Gas Recirculation and Three Way
Catalytic Converter. These 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.
PGM-FI System
The PGM-FI System uses sequential
multiport fuel injection.
It has three subsystems: Air Intake,
Engine Control, and Fuel Control.
The Engine Control Module (ECM)
uses various sensors to determine
how much air is going into the
engine. It then controls how much
fuel to inject under all operating con-
ditions.
208
Technical Information
Ignition Timing Control System
This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
Secondary Air Injection System
During engine warm-up, air is
pumped into the exhaust to reduce
emissions when the engine is cold.
Exhaust Gas Recirculation (EGR)
System
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
2
(N ), and water vapor.
2
Replacement Parts
The emissions control systems are
designed and certified to work
together in reducing emissions to
levels that comply with the Clean Air
Act. To make sure the emissions
remain low, you should use only new
Acura 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.