01 Civic DX

I've Got an 01 civic (dx) and i am trying to find the best way to modify the exhaust. For everyone out there that doesn't know the dx model on an 01 civic has the converter built into the manifold. I can do a complete dx to ex conversion (not at all completely sure if it will work), or i can somehow find a way to modify the exhaust (the whole exhaust) with parts meant for the dx model. "I found out the hard way after ordering an exhaust that was meant for an ex". everyone i have talked too says that i cannot replace the manifold that's on there because it will fail emissions tests during a N.Y.S. inspection. anyone have any useful advice for me?