I gotta jdm mugen header w/2.5" collector. I ordered a universal 2.5"in/out carsound high flow cat. I also got a 2 bolt 2.5" flange that will be welded on the the cat to connect to the header. My question is how do I go about connecting the cat to the 3 bolt flange on my apexi world sport downpipe without cutting of the flange on my downpipe. If I get a 2.5" 3 bolt flange welded on to my cat, will it not be to big? Or will it bolt right up?

Basically i'm saying, if I have a 2.5" 3 bolt flange on my cat will it match up perfectly with the 3 bolt flange on my apexi world sport downpipe? If not what are my options?

Thanks in advance BTW this is on a 00 civic coupe/ with a jdm b16a

 

Assuming it's a standard size 3-bolt flange, it will fit with no modifications. The difference between a 2.5" flange and a 2" flange is not the size of the flange itself (the bolt spacing and overall size will be the same), but rather the size of the flange's opening.

 

ahh i see.... Thanks bro