I stopped in a muffler shop(national chain) to get an estimate. $800+ so I decided I would tackle it on my own. All the parts are ordered and came in today. I have a question, the three studs on the flange after the cat, are they pressed in? I am guessing they are rusted badly so I will need to replace them. Any insight on this would be great! They rest looks straight forward.
Use some PB Rust Blaster or similar to help break them loose, then you should be able to unscrew them. Basically it's penetrating lubricant with a freeze that creates microcracks and then uses them to get the lube deep down. I've used it on some pretty stubborn stuff and was successful.
have the same problem.... are they BOLTS or RIVETS?.... mine are on connector pipe just before the muffler.... hate to beat on it and find out its threaded
Don't bother with PB Blaster or Kroil or anything like that, use a torch to get the nut hot and then try again. The heat will expand the nut, breaking whatever bond has occurred between it and the bolt.
Having taken off more than my fair share of rusted bolts/nuts any time you can use heat, do it. If you can't use heat, use Kroil. Oddly enough, when I was in the USAF the guys in the jet engine shop used plain hydraulic fluid.