EMISSION CONTROL SYSTEM CONTROL EMISSION CONTROL
FUNCTION OF MAIN COMPONENTS
The main components of the 1PP emission control system are as follows.
Component
Function
TWC
Reduces emissions by oxidation of CO and HC in the exhaust gas and reduction of NOx.
Heated Oxygen Sensor
Detects the oxygen concentration in the exhaust gas by measuring the electromotive force which is generated in the sensor itself.
PCV Valve (No. 1 Ventilation Connector)
Controls the flow rate of blowby gas by opening and closing a valve using vacuum generated in the intake manifold.
Purge VSV
Controls the flow rate of evaporative emissions by opening and closing a valve based on signals from the ECM.
ECM
Controls the volume of fuel consumed based primarily on the signal from the heated oxygen sensor, with minor corrections based on the signal from the heated oxygen sensor. This control optimizes the air fuel ratio.
Canister
Contains activated charcoal to absorb the fuel vapor created in the fuel tank assembly.
SYSTEM CONTROL
Blowby Gas Ventilation System
By directing blowby gas containing a large amount of HC through the combustion chamber via the intake, emission performance is enhanced. The volume of blowby gas is regulated depending on the engine operating conditions, reducing the consumption of engine oil and impact on the engine idle speed.
The PCV valve (No. 1 ventilation connector) passage regulates the blowby gas in accordance with the intake manifold vacuum.
A blowby heater prevents the ventilation line of the crankcase from freezing in low temperature environments. Thus, correct ventilation of the crankcase is ensured in all environments.*
*: Models with blowby heater system