Well, I am no plumber... I took out the ugly PVC trap under my wall-hung sink thinking to replace with chrome. The sink and wall tile are from 1955 and the pipe in the wall is 1 1/4". I am quite certain that this sink is original and that the pipe has always come out of the same hole in the wall, but the PVC trap obviously was not. It was 1 1/2" pipe, but as it was going into 1 1/4", I figured I should replace it with an 1 1/4" trap. The problem is that while the 1 1/2" trap was wide enough to reach the wall, the 1 1/4" is not. Yet surely the original piping must have been 1 1/4", so what am I missing?