I've got a long run of 4" pipe that ends at a toilet. My plan was to put a combo wye with a cleanout at the bottom of the stack but I don't have enough room since the foundation wall is only about 15" away. Because of the long run the sweep 90 needs to be real tight to the bottom of the joists. I could put a cleanout after the sweep 90 (see attached dwg.)but that would mean the cleanout points up into a joist bay with joists 16" on center. This is my own home and that placement seems fine to me but is that a code violation of any sort or do any of you plumbing guru's have an alternative??