Reduce CO₂

Reduce PM

Reduce Nox

Reduce HC

Due to complete combustion

Due to incomplete combustion

Due to excess air supplied

Due to atmospheric mixture

Combo of PCV and EGR

Combo of EGR and SCR

Combo of PCV and 3 way catalytic connection

Combo of DPF and EGR

To prevent pressure build up

To prevent temperature build up

To increase the blow by gas

To reduce the combustion leak

Use of back pressure to increase efficiency

HC present in blow by drawn out

HC present in the blow by reused

Increase the crank case dilution