EMISSION CONTROL<MPI>
ENGINE AND EMISSION CONTROL
17-10
A purge control solenoid valve is installed in the inlet
manifold. The purge control solenoid valve controls
the intake volume of fuel vapour gas from the canis-
ter. The purge control solenoid valve is a duty control
type solenoid valve. When current is not passing
through the coil, nipple A is kept airtight and fuel
vapour gas cannot be sucked in. When current
passes through the coil, air can pass between nipple
A and B and fuel vapour gas is sucked in.
Engine-ECU changes the ON duty ratio according to
engine's operating condition to control the intake vol-
ume of fuel vapour gas.
EMISSION REDUCTION SYSTEMS
M2171000800439
These decrease CO, HC and NOx in the exhaust
gases and consist of air-fuel ratio feedback control
and catalytic converter.
1. AIR-FUEL RATIO FEEDBACK CON-
TROL
Refer to GROUP 13A
− Fuel Injection Control .
2. CATALYTIC CONVERTER
The exhaust manifold and the centre exhaust pipe
include a catalytic converter.
Based on appropriate air-fuel ratio feedback from
oxygen sensor, CO and HC are oxidized and NOx is
reduced. Catalytic converter is a monolith with bee-
hive design with catalysts on the unit surface. It is
protected by a thermally insulating mat and enclosed
in a shell.
AK602245AC
12V
ON
OFF
0V
100 ms
Purge control
solenoid valve
From engine control relay
Engine-ECU
AKC00010
AKC00010
Catalytic converter
(built-in to exhaust manifold)
AB
Front exhaust pipe
Catalytic converter
(built-in to centre exhaust pipe)