If you happen to get busted by the inspector then you'll have to replace it properly anyhow. If a state trooper just happens to be around at that time you could be looking at serious $$$ penalties. The EPA and DOT love busting on this stuff. Seriously, it's just an anemic LR 3.9 so gutting the cats isn't going to make huge power gains. You can replace with a new y-pipe which should increase exhaust flow by default. Alternately, you could fit aftermarket small hi-flow cats to decrease backpressure. Fix it right and be done with it.