I have a good cheap fix for a rusted muffler problem. The total
   cost to replace your muffler goes from $130 to about $30,
   and some work.

   Here it is. First at your local FLAP get a hold of their
   Sound Solution exhaust catalog. (Trak had a catalog but
   it took an acted of congress to find someone willing to
   work with me.) In the back you will find      
   a universal muffler part #18696, for about $20. It comes 
   with a small tail pipe and an adapter to 1 7/8" pipe.
   You also need a 3 bolt flange that bolts to the CAT. with a
   I.D. of 2" to go to the muffler. The only flange I could 
   find,  had 2-5/8" from bolt to bolt and 2-1/8" I.D. 
   center hole. Because of this I needed a 2" O.D. to 2"I.D. 
   adapter to go between the flange and the universal muffler. 
   I had to cut about 3/4" off of the adapter to get the proper 
   length. I put every thing togeather, rotated the muffler to 
   sit at the bottom of the c-bracket, and tack welded everything 
   in place. Once welding was completed, I bolted the muffler to 
   the CAT. Last I needed to add some scrap metal to take up 
   the slop in the straps that go overtop of the muffler.
   This muffler works go. It is a little louder at the low end,
   but to me this sounds even better. Just got my PA state 
   inspection, and $100 buck of bear money.