I have a 98 xj limited. I wanted to install a performance exhaust system. But i didn't want to do all with 2 1/2 without headers? I didn't know what people think about the pacesetter cat back systems, but that was where I as going to start. I just need to find some good headers. What real performance gain would i get if I just went cat back. I was thinking about a flowmaster 40 series, but would a pacesetter system be a better gain? Also has anybody used a hypertech programmer yet?