仔細讀了相關規定，暫放博客了待後小結。謝謝各位。

1.聯邦法律沒有限製自己裝，隻說要填寫生產廠家的保證卡給用戶。我理解installer/customer可以是同一家。舊的無須保修，但必須是測試過，賣主需對此負責。新品保證卡是5年/5萬邁外形及2萬5千邁功能。產品上必須有型號標簽。
2.加州法強調聯邦法中要按原類型的說法，但強調不能光看引擎大小與車重（要按原拓撲結構），且必須保正卡。
3.通常隻能在廢氣檢查要求你換時才能換，必須是原類型（3元催化器與否，不是指原型號，）原位置，after market的必須有廠家文字說明用於同型車或是設計用於多種車的。

“ I failed smog in CA and it was the cat and even though the shop that did the first inspection said "they" had to install a new one, they were wrong. I took it to the muffler shop, had them install a new CARB approved cat, went to test only and passed with flying colors. No proof in writing, no nothing. Just ran the smog and passed it and in CA all emission tests are stored in the state computers so the state knew it failed the first time and why.”
http://www.jeepforum.com/forum/f11/replacing-catalytic-converter-yourself-illegal-1020925/