Originally posted by zm830101: you know, i think demon has posted this before, saying that the stock svt main cat actually flows really well and should not be considered a major source of restriction. why not maintain the main cat and eliminate the pre cats with the headers, best of both worlds. performance gain from no pre cats but clean emissions because of functioning main cat. SAVE OUR AIR!! if the main cat is not a restriction why get rid of it. heck if you are that concerned you can replace it with an even higher flowing unit from an aftermarket company but i would hazard a guess to say that only the most highly modified 3.0l and forced fed cars are even really in need of a higher flowing cat.
I think his point was that the stock cat flowed well enough that the difference did not justify buying a high flow unit. No cat will net a few HP, but you wouldn't be legal.
Gutting the precats doesn't net much of a gain that I've observed - I've done it. A good set of headers & an optimized stock Y will give you the best combo for your money, hands down.
