CA cats: They are the SAME cats but if they carry the CARB stamp or suffix, they have to be warranted for 100,000 miles, not 30K like the old "49 state" value. So its just the warranty you are buying for 3X the price with the CARB stamp on them
There was something to that effect noted in the CO (or should I say CA) law. That the cats with out the CARB rating were failing at a quicker rate so CO decided to require the CARB cats.