Having 'been there', I'll give you a heads up to help you.
Fabricate or have someone fabricate a catalyst just like this:
The catalyst adds a very small amount of muffling to the car and is a straight through honeycomb design for minimal backpressure.
Do whatever you want to the car for performance.
Lean it out for emissions and *stay off the boost* during that time.
3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ -
"930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe
Movie: 930 on the dyno