A couple of other uses for dealerships 1-To buy a new truck, 2-To buy dealer specific parts. Otherwise, any place else is better.

 

Unless you need to acually replace the pipe in the cross-over manifold , you can get 2-in-1's that will work fine to to replace the cat . They can be had on Ebay for cheap , search magnaflow .
I had a hollowed cat but it sounded like an old school bus , garbage , I wasn't happy . I just got back from the shop where I had a 2-in-1 installed , plus an 02 bung , sounds freaking great now .

Thought I'd mention it , it's a heck of alot cheaper that replacing the y-pipe , dealer or not . If you want pics , PM you email to me , I'm really ltd for space on here

 

id just remove the cat, mine's gonna go, just gotta measure the y-pipe size i need, on the inlet size