all cobb downpipes come catted.. and u can find a used on on the foruims for way cheaper than new.. also it comes with wideband 02 bung already saving u moeny to buy a bung and have somone weld it in.. not to mention when you flash to a stage two map (with an AP i cant comment on open source), it takes care of any codes u mihgt throw.. NJ used to have super strict emissions and i went through inspection more than one with zero cats on my car...