yeah, i got a snake nearly all the way thru to where it joins up with the main sewer piping, but i have pulled out a bit of mud and i can't seem to get any further (there's another 90 deg bend that i think is keeping me from getting thru)

so i picked up some pipe, a new one-way valve while i was at it (the old one had been semi-busted for a while), assorted fittings, and some pvc cement and i'll rebuild that last corner and pull whatever cruft out of it i can and make it more snakable in case this ever happens again.