listen here, i got a eg coupe with a jdm gsr and a short dc header for a 94-98 gsr where it has no 02, so today i got a long dc header from a 99-00 si with the o2, now its longer, do i have to shorten my exhaust? or can i change my cat to a 2000 si and call it a day? either way that **** is goin on in the mornin even if i have to go to the muff shop cause gas is to fuccking expensive.