After researching for months I finally bought a used 07 STI uppipe for my 04 wagon. I felt $60 was better than me cussing and busting knuckles removing the Cat. So I got my new gaskets and decided I'd take it to my mechanic instead of me suffering for a day or so. I have some tools and jack stands, but really no help unless you count the wife pumping the breaks when I installed SS lines, lol. So after it was all done $60 for the Up, $30 for gaskets, and $268 to Dixie Dan for labor. The only work I did was the resistor mod before the work was done.
I am very pleased with the sound and throttle response. My gas mileage is better, too.