can somebody help me ? i bought a 2006 quad cab with a 5" cat back exhaust and iam trying to get a 5" turbo to cat exhaust i have to leave the cat on because they smog the truck(BIG SCAM HERE IN LAS VEGAS!!!) any way what i need is an adapter that will go on to my cat from 4" to 5" because my cat is currently 4" from the turbo please help with any ideas iam new to this form it looks cool thanks

 

In my experience, they just cut your cat at each end to 5" inlet and outlets and weld the new pipe to it. Your cat is tapered on each end so it isn't hard to get the right diameter for this. If you use a reducer to go from 5" down to 4" through the cat then back from 4" to 5" then in my opinion the 5" down pipe from the turbo to the cat is a big waste of time, money and effort.

BTW, welcome to DB.

 

if you have to keep the cat then just go 5'' from the cat back it would be cheaper. btw