Technically speaking all long tube headers are illegal in all 50 states.
According to federal law you cannot remove/relocate your factory catalytic converters and long tubes force you to relocate them, so by driving with long tubes on the street you are violating federal law.
That said - in some states they don't check or don't care, however it's still federal law so technically it's illegal. Since CA is super anal about that type of **** you would probably run into trouble.
Up here in MA the inspection station is supposed to plug in via OBDII to check the emissions and do a visual inspection (so long tubes SHOULD fail) however most places don't do the visual; as long as you pass via OBD you're OK. I know my inspection guy and he doesn't give me any trouble for any of my vehicles so I just have to pass the OBD scan, which is why I'm still considering long tubes even though I live in a state that can be a PITA about this type of thing (I'm just aiming to get the quietest set of long tubes & mid pipe I can find, so I don't attract attention from cops who could still ticket me for illegal exhaust - though that's pretty rare too).