You may have a plugged Catalytic Converter. Do you ever get a check engine light blinking or staying on? If so, get those codes read, that will be a big help.
here are some shops:
https://repairpal.com/hyundai-repair-in-sarasota-florida
RepairPal Certified shops can diagnose and repair your 2001 Hyundai XG300. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.