Probably not at any old muffler shop, but should be okay at a high-quality shop. If you can't find the right place in PDX, hop over to Hazel Dell Muffler in (you guessed it) Hazel Dell -- I-5 exit 4, merge right from the ramp onto 78th street, left at the light onto old hwy 99, go about a block and it's on the right.

I took our 122 there without any exhaust mounting hardware, and it came back with those whale tail things and those rubber donuts. There should be a second set where the tailpipe goes past the gas tank, BTW.