What size aftermarket cat?

[darktalonz]

I have an apex n-1 downpipe and i'm going to be moving to a state with inspections. So the question is what size cat would i need to weld into the downpipe?

Thanks
Garett

 

[nine5raptor]

the same size as the rest of your exhaust

 

[darktalonz]

Why thank you for the help but i can't measure it right now because i'm about 5,000 miles away in a different country. So I thought i would check and see if anyone actually with the N-1 downpipe would actually know what size i would need.
Thanks

 

[L2RTSiAWD]

Well I heard it's 2.5 right at the cat area then opens to 3inch. Or is it 3inch at the cat then necks down to 2.5 at the muffler?

Now i'm confused.

 

[nine5raptor]

I think it goes 2.5 before the flex to 3" then in the muffler it goes back to 2.5 inside the backend (near the tip)