Ka mana hoʻoheheʻe
ʻO ka loiloi o ke ʻano o ka ʻaʻahu o ka catalyst, ʻoihana i ʻike ʻia ʻo ka catalytic converter, i hana mau ʻia e ka ʻōnaehana diagnostic ma luna o ka papa, aia i ka nānā ʻana i ka hoʻololi ʻana o ka ʻike oxygen i nā kinoea hoʻopau ma mua a ma hope o ka catalyst.
No kēia kumu, hoʻohana ʻia nā hōʻailona i hoʻouna ʻia e nā mea ʻike oxygen (ʻike ʻia ʻo lambda sensors). Hoʻokomo ʻia kekahi o nā sensor i mua ona 
catalyst a me ka lua hope. ʻO ka ʻokoʻa o nā hōʻailona ma muli o ka paʻa ʻana o kekahi o ka oxygen i loko o ke kinoea hoʻopau ʻia e ka catalyst a no laila ʻo ka ʻike oxygen i loko o ke kinoea hoʻopau i lalo o ka catalyst. Kapa ʻia ka hiki o ka oxygen o ka catalyst ka hiki o ka oxygen. Hoʻemi ia i ka wā e komo ai ka catalyst, e alakaʻi ana i ka hoʻonui ʻana i ka nui o ka oxygen i loko o nā kinoea hoʻopau e waiho ana. Hoʻololi ka ʻōnaehana diagnostic on-board i ka hiki o ka oxygen o ka catalyst a hoʻohana iā ia e hoʻoholo i kona pono.
Hoʻohana nui ʻia ka sensor oxygen i hoʻokomo ʻia i luna o ka catalyst e hoʻomalu i ke ʻano o ka hui ʻana. Inā ʻo kēia ka mea i kapa ʻia ʻo stoichiometric hui ʻana, kahi e like ai ka nui maoli o ka ea e puhi ai i ka nui o ka wahie i ka manawa i hāʻawi ʻia me ka helu theoretical i helu ʻia, ka mea i kapa ʻia ʻo binary probe. Hōʻike ia i ka ʻōnaehana hoʻomalu he waiwai a lean paha ka hui ʻana (no ka wahie), akā ʻaʻole i ka nui. Hiki ke hana ʻia kēia hana hope e kahi mea i kapa ʻia ʻo broadband lambda probe. ʻO kāna ʻāpana hoʻopuka, e hōʻike ana i ka ʻike o ka oxygen i loko o nā kinoea hoʻopau, ʻaʻole ia he volta e hoʻololi i ka stepwise (e like me ka ʻimi ʻelua-kūlana), akā ʻo ka hoʻonui ʻana i ka ikaika o kēia manawa. ʻAe kēia i ka hoʻohui ʻana o nā kinoea hoʻopau e ana ʻia ma luna o kahi ākea o ka ratio o ka ea, ʻike ʻia hoʻi ʻo ka lambda ratio, no laila ka huaʻōlelo broadband probe.
ʻO ka lambda probe, i hoʻokomo ʻia ma hope o ka catalytic converter, hana i kekahi hana ʻē aʻe. Ma muli o ka ʻelemakule o ka mea ʻike oxygen aia i mua o ka catalyst, ua lilo ka hui ʻana i hoʻoponopono ʻia ma ke kumu o kāna hōʻailona (electrically correct) e lilo i leaner. ʻO kēia ka hopena o ka hoʻololi ʻana i nā ʻano o ka probe. ʻO ka hana a ka lua o ka oxygen sensor ʻo ia ka mālama ʻana i ka haku mele ʻana o ka hui ahi. Inā, ma muli o kāna mau hōʻailona, ʻike ka mea hoʻokele engine i ka wīwī loa o ka hui ʻana, e hoʻonui ia i ka manawa injection e like me ka loaʻa ʻana o kāna ʻano e like me nā koi o ka papahana hoʻokele.
