Not to take this post away from the op , but I got a question. These aftermarket suppliers all say cat-back , but all it is , is a muffler and tailpipes.
On these 5.7 's, the cats are way up on the y-pipe. I was thinking of cutting the y-pipe down near the actual y (about 6-12 inches),and creating an actual true dual setup from there back.
Why would that void a warranty,and if so,where can I get info on why?
Sorry op ,now back to your question. Thanks
The only part of the warranty you'd lose by doing this is on the portion of the exhaust you removed.
You will lose power with duals though, unless you also install a crossover.