Besides being (I would guess) slightly more crime-friendly than other places, I'll bet part of the problem is the expense of catalytic converters in CA. They are probably worth a lot more as spares than as raw materials.
It seems to me that CARB forces people to buy OEM parts, or at least some kind of on-a-list part for $$$.
It seems to me that CARB forces people to buy OEM parts, or at least some kind of on-a-list part for $$$.