Am trying to remove the muffler from the long exhaust pipe on my '99 so I can re-weld the tip back on and make it easier to reassemble under the car. I've removed the clamp nut and the main pipe (the long one that contains the catalytic converter) seems to be a slip fit into the flared part of the muffler itself. It will wiggle side to side and slides out about 1/4 inch but no further. There is what looks like a locating pin to align the pipe and muffler - am I missing something here? Is this some sort of rivet or fixture?