I searched and couldnt find anything in the B6 thread, but will an electronic cutout work on a 3.0 quattro thats stock? If so, what size

 

What is that?

 

a y valve thats electronically controlled, installed just before the cats. when opened, your car runs on straight headers. when closed, it runs off whatever exhaust you have. anyone have this on their audi?? if not, anyone know what size the stock pipes are? I would assume 2.5in?