仔细读了相关规定，暂放博客了待后小结。谢谢各位。

1.联邦法律没有限制自己装，只说要填写生产厂家的保证卡给用户。我理解installer/customer可以是同一家。旧的无须保修，但必须是测试过，卖主需对此负责。新品保证卡是5年/5万迈外形及2万5千迈功能。产品上必须有型号标签。
2.加州法强调联邦法中要按原类型的说法，但强调不能光看引擎大小与车重（要按原拓扑结构），且必须保正卡。
3.通常只能在废气检查要求你换时才能换，必须是原类型（3元催化器与否，不是指原型号，）原位置，after market的必须有厂家文字说明用于同型车或是设计用于多种车的。

“ 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/