You may want to inspect your engine mounts. If the factory rubber mounts allow the engine to rock with throttle application. This twisting motion will eventually cause the side pipe bracket to fracture! As a test, You could unbolt the side pipe brackets, next grasp the collectors just at the point of exiting the body and rock the engine, If the engine moves back and forth I would consider replacing the engine mounts. polyurethane engine mounts may help with these broken side pipe brackets. Hope this helps.
