Hey guys, last week my 2001 Acura MDX started sounding like a super up Civic but not check engine light. Took it to a shop thinking there was a hole in it. Was told that my catalytic converter was bad and needed to be replaced. Took it to a different shop and was told that the catalytic converter was fine but the flanges were so badly rusted that I'd have to get a whole new converter. My friend looked at it and took the heat shield off and finally was given a end answer. The flanges that were bolted between my catalytic converter and flex pipe were fine however the bolts that were holding them together were rusted and breaking off. My friend cut off the bolts but couldn't remove them from inside the flanges (tried an air chisel and torch, nothing worked). My question is what size bolts do I need to replace those and how do I get those rusted bolts out?