I'm getting a Dynomax 17495 catback w/ the 3" inlet. I will also be getting a Hedman y-pipe 17470 with a 2.5" outlet (already have the Hedman shorties). The question is, is a converter available for this or am I going to have to play around with the exhaust to fit from the 2.5" outlet on the converter to the 3" inlet on the i-pipe.

 

Cat converter? If so buy a 3" cat. On ypipe end they make adapters to go from 2.5 to 3". Weld on or slip on styles. Id's or od's they are out there. Even places like pepboys autozone etc have some basic 2.5-3" adapter pieces you can use