I have 2012 xc60 FWR. The connectors between muffler and Catalytic converter separated. The noise is very loud. I connected them together with wires wrapped around. Seems there are six bolts? They are very rusty. Not sure what they should look. Are they bolted together. Anyone knows. What’s the specifics of the fasteners? Thank you.

The circled side + muffler is separated, which make loud noise

 

if the flange to cat welds are still good, you should be able have new bolts installed. On some cars the bolts are welded in - so if they are rusted or broken off, they need to be drilled out and replaced with a through bolt. Nothing special on the bolt itself, just the appropriate size.like an M8. I'd also recommend OEM or automotive bolts vs generic hardware store bolts

 

thank you sir. I did not see the bolts on the catalytic side. Maybe they all gone. There are no obvious bolts on Muffler side, either. But the end are bigger than the holes. They might just rusted out. I will try to drill through and put stainless steel bolts. Thank you again

 

Update! Seems the studs were welded on flange at catalytic side. After removing the rusts on the other ends. seems there is no threads left. Tried to drill and punch out. They were made of strong tough steels. My drill could not make a dent. Tried to make new threads on muffle side. Did not work either. Finally I left old studs as is. Add two pieces of metal plates on top of two middle studs and bolted the metal plates together. Seems very strong.

Also noticed that the the metal welded on the exhaust pipes are almost rusted out. I mean the part:
One end welded on pipe, the other end on rubber hanger insulator. anyone knows what is the parts number?
I might order some. Ask a local shop to welded. I did not see any other structures to support the weight of the exhaust pipes. Temporarily I add a long and strong spring hooked on two holes on either side of muffler or resonant, which should support the weight of whole exhaust system in case those metal hangers fails.