I am installing a new drain for my washer, I have the pic that Terry posted and plan on making mine look the same. I had an utility sink in place before and will put it back when all is finished. My previous drain was 1 1/2"in the wall and under the house for approx 5', then 2" for 30 inches, then into the main 4" drain. I will replace all of the 1 1/2:" with 2" and install a vent through the roof. The old vent was about a 2' pipe inside the wall. On the horizontal run under the house, there is a clean out about 5' from where my drain goes through the floor. At this connection is where the reducer is to go down to 1 1/2". I plan to install 2"ABS to this point after removing the reducer. Is there anything else I need to do to do this the right way? The old pipe got pushed down from removing the nipple above the floor, That is why is is sloped in the wrong direction. I will slop my new pipe 1/4" per foot when I install it.