Originally Posted by michaeldch
So I ran into a problem last weekend. The nuts which connect the downpipes to the midpipe were amazingly rusted. It was so bad that despite soaking for hours in PB blaster both lower nuts stripped when I tried to remove them. I ended up having to cut the nuts with half the stud off. Next step is to get the remains of the stud out of the downpipe flange... And that seems to require downpipe removal. I found a nice looking DIY for that (specifically for the xi). Never a dull moment :/
The same happened to me, I did drill mine out without removing them, but they are a bitch. As hardened steel.
Normal drills will not last, you best need something like a tungsten drill. I used a lot of normal 6mm drills and it took me about 5hours.
Then I bought a tungsten 6mm mill and could grind them out as you see in the pic.
If you have acces to a cutting torch you can heat them up and and burn or hammer them out, but take care of your turbos.