My question is concerning the drain arrangement shown in the attached pictures. One drain is a 2" pipe for washing machine water outlet. The other drain is a 1.5" pipe for a wash sink that is next to the washing machine. Pic #1 shows both drains with their traps. Both pipes dump into a 2" vertical pipe (Pic #2). The vertical pipe goes up to vent and down into a 3" pipe using a wye fitting (Pic #3). This has been like this since we have lived here and seems to work fine. I am finishing the basement and am curious if it meets code. Thank you for your help. Gary