I have DC 4-2-1 headers for my single. I got an exhaust the other day that came off a civic coupe just like mine, but the piping to the exhaust is 2.5 inches and the headers collector is only 2 inches, so it would not be able to fit without leaking all the exhaust from the headers. I think the exhaust, when the cat was welded on, may have been welded for a B series swap, but anyway, my question is there anything I can do to make it work without having to get it rewelded? Is there a special gasket I can get that will keep the exhaust from escaping around where they connect? Also do all d series aftermarket headers have a 2 inch collector, seems kind of small for a perforance header, even if its just a single. Any help is appreciated.