Originally Posted by mkoesel
No, its because you can't register the car in CA if it does not have california emissions equipment (and many cars bought outside of CA don't).
This is also a reason although I think there might be certain allowances. If you've owned the car for longer than a certain number of years, you might be okay, but I am not sure. But if you've had it just for 6 months, I'm sure you'd have to modify things.