Well Robs pipes at $899. remove the 4 cats. Doesn't seem cost effective to do that since it could make selling the car harder if it should come to that. I was considering this option, then removing the resonator and going with a Borla Muffler. $1000. plus labor. So you are in effect saying that Robs downpipes without cats yielded you 26hp total? Seems like a lot, he only claims 15 hp for those downpipes. Anyone done a complete like I have described. THX