Hi:
Got a 1997 Suby OB. About every year it starts making a weird sound. Kind of a twangy rattle. We take it in and they say it's the heat shield. They either "Tighten it" for free, or replace it once in a while for about ten bucks. The fix never lasts for long though. What is this thing & where is it located? Its making that sound once again.
~~Phil~~