hey im trying to find a good header that isnt to much that has a 2.5 inch outlet and then i need a high flow cat that has a 2.5 inch inlet and 2.25 inch outlet beccause i have a magnaflow 2.25 catback hit back with some info peace out

 

yes you are bottlenecking your exhaust

 

so what should i do instead just get a 2.25 header with a 2.25 high flow to match the catback??

 

depends on you're setup. i have stock b18c with hks knock off filter. installed a dc jdm type r header and jackson racing hi-flow cat...i dunno what size cat, but this was very noticeable. oh yeah, exhaust is STOCK! no bumblebee noise...j/k

 

That would be fine. you dont want a 2.5 inch catback unless you have a killer all motor.