Thanks for the help!

 

Yep, just did this on my 04 CTT... came off of a 2008 GTS that had PSE (Porsche Sport Exhaust). There is a very slight difference in diameter - to explain, where the GTS mid-pipe attaches to the CTT secondary cat the sleeve used by the factory to attach the two would not fit 100%. The GTS exhaust is about a 1/4" smaller so what I did was get rid of the sleeve and just have the GTS mid-pipe section go into the secondary cat pipe (I am using Fabspeed bypass pipes) and they fit snug. Did a quick weld of the two sections and was good to go. The muffler and piping was a direct fit. I doubt the slightly smaller diameter will make much difference for performance, but the sound of the PSE was worth it!

P.S. Just noticed you are in the bay area... if you want to see and hear in person just let me know!