Tubes for the EGR system (exhaust gas recirculation) can break, causing an exhaust leak and noise under the hood.
Car Problem Reports
Ford Bronco EGR system tubes can break and cause leak/noise
Ford Bronco Problem
Exhaust & Emissions Affected: 5.8L V8
Average Mileage: 179,254 mi (145,264 mi - 207,500 mi)
Visitor, 1996 Ford Bronco, 185,000 mi
replaced the tube. pulled exhaust manifold thinking it was the culprit and it was the tube. Always check the tube before pulling manifold