I guess this is simple compared to a lot of the DIY work here, but I can't find all the answers searching the archive. I want to move a kitchen sink 30" down the wall and run the drain through the cabinets to the new location. I've found a post saying 42" is the limit for an arm, so I'm good there I think, and the pitch is no problem. I have 2 questions: Since the pipe in the wall is 2" should I make the arm run 2" also because I can, or step it down to 1 1/2 at the wall because it makes no difference? The other is that I am under the impression from reading here that the horizontal bend into the wall from the arm needs to be a wide radius bend. Is this true, and should I use a tee-wye there and put a cleanout plug on it? That would make sense, but I have no idea if its required.