lol, I dont say that to discourage, but that was the only thing on my 89 pathy i didnt do. When i priced out the parts it would have cost me about the same as to take it to someone who specialized in it. In my case(albuquerque, nm) there is a part of town with alot of mechanics at real cheap prices. The only thing I did was purchase a cherrybomb for 40 or so, and let them do the rest, this included catalytic. Think total i paid 250 or so
now if your talking about the exhaust manifold, then i would hit a scrap yard, or use your old ones, either way check to make sure they dont have to be machined.