Yes, the cat is restrictive, but the Cobb 3" downpipe has a section that necks down to 2.5" for a short duration. There
are thread in the engine forum that discuss downpipes at length. I'm not saying to go out and buy a different one right
now, but that you should maybe consider what turbo you would possibly install in the future when choosing another
downpipe. Either way, idk if the Cobb downpipe would flow enough to reliably make 450-500whp anyway.
Btw, I'm totally not trying to be a downer here.