It's WAAAAAY up there, for anybody to get to it from underneath, no? At least when I've changed my oil, I don't see a way to cut it out, but maybe I'm wrong. Now that the EPA requires the CAT to basically be right after the exhaust manifold (or the turbo, in our case), it's tucked up higher than before. Plus, there's hardly any space up there to cut the upper part IMO. At any rate, the most elegant and practical way to block that area, would be with a metal shield that extends under there IMO.