One problem related to catalytic convertor has been reported for the 1998 Chevrolet Blazer. The most recently reported issues are listed below.
Loud sound during acceleration (catalytic converter shot again not replaced, contacting gm, no assistance), oil leak on front of engine (power steering pully shaft seal), noisy ac compressor(replace), fluid leak on front of rear differential (replace yoke and seal [2nd seal]), rear differential clunks on acceleration (change case and shaft bearing), dash grill cracked, ideler arm replaced again.