:scratch: When I looked underneath an 05 Gt I noticed only 2 cats and it appeared to be more free-flowing in contrast to its predecessor. I read somewhere that the new GT has 2.5 Mandrel Stainless Steel Exhaust throughout. Is this true? ANd if so, that is great. What would be the point in upgrading to a complete catback when you already have 2.5 inch stainless steel. I can see the logic in replacing the mufflers, however. Also, the stock H-Pipe with only two cats looks free-flowing to me. I am sure that an Xpipe would enhance performance but not by much. What do you think.

 

Yes, its 2.5" Stainless mandrel-bent exhaust tubing. Unless you need to replace it for larger 3" tubing(i.e.serious engine work and a blower)it should be ok for pretty much anything. Replacing the H-pipe and mufflers should be all anyone nneds to do B)