Modifications to the
combustion chamber, intake manifold, camshaft and ignition system form the
basic control system.
These items have been
integrated into a highly effective system which controls exhaust emissions
while maintaining good driveability and fuel economy.
AIR/FUEL MIXTURE CONTROL SYSTEM [MULTIPORT
FUEL INJECTION (MFI) SYSTEM]
This in turn allows the
engine to produce exhaust gases of the proper composition to permit the
use of a three way catalyst. The three way catalyst is designed to convert
the three pollutants (1) hydrocarbons (HC), (2) carbon monoxide (CO), and
(3) oxides of nitrogen (NOx) into harmless substances. There are two
operating modes in the MFI system.
| 1. |
Open Loop air/fuel ratio is controlled by
information programmed into the
ECM. |
| 2. |
Closed Loop air/fuel ratio is adjusted by the
ECM based on information supplied by the oxygen
sensor. |
