exhaust question

[NSolano]

I am putting on my exhaust within the next week. I am going to buy a Catco Catalytic converter, the question I have is does the catalytic converter have to be the same width as the piping and the same as the muffler piping??
My piping is 2.5 inches, do I have to buy a 2.5 inch cat?? do all the pipes have to be the same width or do they change?
I know its some stupid questions but i just want to save money, so I am not buying the whole exhasut system, i am buying it in parts.

[Bliggida]

Yes you buy the same size. The only place they differ is ID and OD...

Inner Diameter and Outer Diameter. So a 2.5 OD won't fit up to a 2.5 OD without a 2.5 ID sleeve.

Normally, where you have a 2.5 OD, a 2.5 ID will slip right up over it.

But then again, ID or OD, any competent exhaust shop will have a tubing stretcher and will simply flair whichever end neccesary to make your new cat either be ID or OD, depending on what your pipe size is - ID or OD.

[daWhoady]

If you are getting a 2.5" exhaust, then just get a 2.5" in/out Catco Cat. The cat will have to be welded on, so you don't have to worry about any OD or ID. Whichever exhaust shop you take it to will make it work.