Emission Control Systems; System Purpose - Toyota 4-Runner 1985 Repair Manual

EC-2 EMISSION CONTROL SYSTEMS (EFI) -
System Purpose
SYSTEM PURPOSE
System Abbreviation
Purpose
Positive crankcase ventilation
PCV Reduces blow-by gas (HC)
Fuel evaporative emission control EVAP Reduces evaporative HC
Dash pot * DP
Reduces HC and CO
performance at idle
Exhaust gas recirculation EGR
Reduces NOx
Three-way catalyst TWC Reduces HC,CO and NOx
Electronic fuel injection
EFI Regulates all engine conditions for reduction of
exhaust emissions.
Remark: * MIT vehicles only