ok so i have a 96 civic, with a b18c gsr swap in it, i ordered an apexi n1 exhaust and megan headers for it plus i have a megan cat too. the n1 exhaust is for a 92-00 honda civic ex/si it said, and the headers are for a gsr, which is what engine i have. and the cat is for a gsr also. i put it on today and the down pipe from the headers will not fit onto the flange for the cat, the holes line up kinda, but the downpipe holes are a lot wider than the holes on the flange on the cat. so my question is what do i need to get rid of this leak? do i need a different flange welded on my cat or do i need a cat that fits a megan header? any help is needed. thanks

 

i would just bring it to the muffler shop and have them weld on a matching flange, shouldnt cost too much