This engine is basically the same as the conventional 4B1 engine. The exhaust gas recirculation (EGR) system is added.


Exhaust gas cleaning devices list
Objective / Function
Composition parts
Crankcase ventilation system
HC decrease
Re-combustion of blow-by gas.
Positive crankcase ventilation (PCV) valve
Evaporative emission control system
HC decrease
Re-combustion of blow-by gas.

  • Canister
  • Purge control solenoid valve

Exhaust gas recirculation system
NOx decrease
Reduce NOx generation by controlling EGR volume according to engine warm-up condition and driving conditions.
Exhaust gas recirculation valve
Emission reduction systems
Air-fuel ratio feedback control
Decrease of CO, HC and NOx
Controls air-fuel ratio of air-fuel mixture to become theoretical air-fuel ratio (about 14.7), which is when the 3-way catalytic converter’s cleaning performance is best. It also controls optimum fuel supply based on coolant temperature, driving conditions etc.

  • Engine-ECU
  • Air flow sensor
  • Injector
  • Linear air-fuel ratio sensor
  • Oxygen sensor (rear)
  • Crank angle sensor etc.

Catalytic converter
Decrease of CO, HC and NOx
It facilitates oxidation of CO and HC and reduction of NOx so that all 3 component gases are cleaned simultaneously.
Monolith catalyst