The motorized seat belt may chatter or become jammed in its track and not operate properly; Hyundai issued a recall for 1990 - 1994 model years that should correct this concern.
Resources for the Repair and Maintenance of your 1991 Hyundai Sonata
1991 Hyundai Sonata
1991 Hyundai Sonata Problems
Miscellaneous -- Verified
Recent Repair Estimates