Catalytic converters

That is for newer vehicles, ie 2021's! so you cant buy a new car in Nevada and bring it on over with 400 miles on the odometer. Must rack 7500 miles...and the older Fed cars must pass CA smog limits, not the Fed limits they were built to pass if you wanna register them here. I know the carb main jets and bleeds are different in CA spec/Fed spec in my carb book. So you must tweak your Fed smog to pass tighter CA smog in order to register it here. May be as simple as a few jets. How this doesn't get into interstate commerce laws (ie. Minnesota Mud Flap law) is a mystery to me. Iirc MML was a supreme court ruling that stated no state can impose onerous laws (ie round mud flaps) preventing other states from transporting goods through their state or something like that.