Chosinthira chothandizira ndicho chida chofunikira kwambiri choyeretsera chakunja chomwe chimayikidwa muzitsulo zotulutsa mpweya, zomwe zimatha kusintha mpweya woipa monga CO, HC ndi NOx kuchokera ku mpweya wotulutsa kukhala wopanda vuto la carbon dioxide, madzi ndi nayitrogeni kudzera mu oxidation ndi kuchepetsa.Pamene mpweya wotentha kwambiri wa mchira umadutsa muzitsulo zoyeretsera, wothandizira woyeretsa mu chothandizira adzawonjezera ntchito ya CO, HC ndi NOx ndikuwalimbikitsa kuti azichita zinthu zina zochepetsera makutidwe ndi okosijeni, momwe CO imapangidwira kuti ikhale yopanda mtundu komanso mpweya woipa wa carbon dioxide pa kutentha kwakukulu;HC mankhwala ndi oxidized kuti madzi (H20) ndi mpweya woipa pa kutentha;NOx imachepetsedwa kukhala nitrogen ndi oxygen.Mipweya itatu yowopsayo imakhala mpweya wopanda vuto, kotero kuti mpweya wa mchira ukhoza kuyeretsedwa.

Chonyamulira mbali chothandizira ndi chidutswa cha porous ceramic zakuthupi, amene anaika mu chitoliro wapadera utsi.Amatchedwa chonyamulira chifukwa satenga nawo gawo pazothandizira, koma amakutidwa ndi platinamu, rhodium, palladium ndi zitsulo zina zamtengo wapatali.Ikhoza kusintha HC ndi CO mu gasi wotuluka m'madzi ndi CO2, ndikuwola NOx kukhala nayitrogeni ndi mpweya.HC ndi CO ndi mpweya wapoizoni.Kukoka mopitirira muyeso kumabweretsa imfa, pamene NOX idzatsogolera mwachindunji ku photochemical smog.

Pansi pa ntchito yachizolowezi chosinthira chothandizira, chifukwa cha kuchuluka kwa kutentha komwe kumapangidwa ndi makutidwe ndi okosijeni, magwiridwe antchito a chosinthira chothandizira angayesedwe ndi kusiyana kwa kutentha.Kutentha kotuluka kwa chosinthira chothandizira kuyenera kukhala osachepera 10-15% kuposa kutentha kolowera.Kwa otembenuza ambiri abwinobwino, kutentha kwa chosinthira chothandizira kudzakhala 20-25% kuposa kutentha kolowera.

Chisa chachitsulo chothandizira gawo lapansi chili ndi ubwino wowotcha mofulumira, voliyumu yaying'ono, mphamvu zamakina apamwamba, kukana kutentha kwambiri, ndi zina zotero. Amagwiritsidwa ntchito kwambiri pa njinga zamoto ndi galimoto (injini ya petulo ndi injini ya dizilo) yotulutsa mpweya.Titha kukumana ndi muyezo wotulutsa Euro II, Euro III, Euro IV, Euro V, EPA ndi CARB.