EXHAUST
EMISSION CONTROL SYSTEM
THREE WAY CATALYTIC CONVERTER
The three-way catalytic converter system, which is installed downstream of the exhaust
manifold <134, 135> or beneath a turbocharger and under floor <4G1>,
oxidizes CO and HC and reduces NOx. The catalyst consists of a honeycomb-shaped monolithic carrier
whose surface is covered with catalytic elements. It is supported by a heat-resistant mat and
enclosed in a shell.
AIR-FUEL RATIO CLOSED LOOP CONTROL
The system effects air-fuel ratio feedback control on the air-fuel ratio to achieve the
stoichiometric air-fuel ratio (approximately 14.7:1) in which the three-way catalytic converter’s
reduction capability can be brought into the best. For details, refer to GROUP 13A - Emission
Control - Fuel Injection Control 
<134, 135>, 13B - Emission
Control - Fuel Injection Control <4G1>.