only 2. Not 6 like an older mustang.
Greydiesel, that is actually debatable. Yes cats do good, but they also do harm. So it's a which one's worse type deal. Without the cat, the car puts out hydrocarbon, carbon monoxide, and nox, which cause smog and are potentially harmful to people. With the cat, it puts out c02, which is the gas that is causing the supposed global warming. That's why they are actually considering phasing OUT cats, or at least finding a different type of catalyst. But just for the record, I think the co, nox, and HC are worse than c02, at least in my opinion.