Be used to replace and purify tail gas of automobile or motorbike While engine replaces tail gas through exhaust pipe, CO、HC、and NOx go through purifier made of multi-hole cordierite catalyst honeycomb carrier, it make the 3 gas more active and do oxide-reducing chemical reaction. And CO is oxidized into no color and no poison CO2 under high temperature. HC chemical compound is oxidized into H2O and CO2 gas. NOx is restored into nitrogen gas. The three kind of poisonous gas are made into unpoisonous gas to make them pure.