I too have a cracked exhaust manifold on my '98 with 122,000 miles. The mandrel coming off the #1 cylinder is broken all the way around, leaking exhaust, although it is not extremely loud in the passenger compartment.
The local junk yard can get me a used one for $135, and online you can buy a new manifold for about $185 plus shipping. The great thing is the 1st gen Ody's are probably the easiest vehicle in the world to change an exhaust manifold.
-Ken-
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Follow up on above post:
Just finished replacing the manifold. Took me about 45 minutes which included cleaning up the engine block surfaces and installing new gaskets. I keep thinking I must have done something wrong since it went way too easy.
I was able to find a used one in perfect shape from a junkyard back in Arkansas for $100 shipped. Amazing what the Internet can do.
Found out why the manifold cracked: A bolt that attaches the small bracket from the manifold to the block was missing. Either it fell out by itself (unlikely) or a previous repair forgot to install that bolt. Without the support from the bracket, the manifold and header would likely slightly flex with normal operation. So if your exhaust manifold is cracked, then make sure that bracket is attached properly.