One problem related to manifold/header/muffler/tail pipe has been reported for the 1998 Toyota Tacoma. The most recently reported issues are listed below.
Under 50,000 miles exhaust pipe broke, this was welded and repaired. Under 70,000 a hairline crack that encircles the pipe was behind a welded bracket broke again for a second time, this was welded again for repair. The 3rd time 170,000 broke again and this pipe was replaced entirely . Now the 4th time, at 178,000 miles this has broken again. This is awaiting a replacement.