Guys,
I am replacing the muffler assembly on a 99 Civic EX with the V-TECH engine. When taking the muffler off, I tried unbolting the hardware from the muffler side of the flange (where the small coil springs are on the special bolts). Well, both of the "bolts" broke off just where the threading starts on the. Yes, the muffler is off, but the remainder of the hardware is still in the nuts that are on the flange coming from the resonator. My question is this. Are the nuts on the resonator side of the flange welded on to the flange itself or are there supposed to come off? I got onto them pretty well with a 15mm wrench and they didn't want to budge. If these are welded onto the flange, how do I go about removing the rest of the bolt? There is about 3/4" of the bolt sticking out the back of the nut and I tried, with no luck, to spin them out with a pair of vise-grips. Any help will be graetly appreciated.

Thanks in advance,
Todd