I am currently finishing a bathroom project that involves installing a pedestal sink. I ran into what seems to be a problem. The drain trap assembly that was on the old sink has a small threaded plug at the bottom of the bend. It appears that it rusted out and now leaks. I was going to replace this peice of the trap, but the threads on the new peice don't match up with the threads on the old on. There is still a but on the J part of the trap sticking out of the wall. This is where I'd like to add the replacement trap, but the threads don't match. The piping is 1 1/4" as far as I can tell. I don't know what to do because I can't replace the whole trap assembly since it goes into the wall which has just been re-finished and painted.