First time I'm using this forum... I am doing a remodel with approximately back to back kitchen and lavatory sinks. The 2" drain and vent pipe is offset with a 2"x2"x2" sanitary tee to attach the 2" horizontal drain line to. I am considering attaching a 2"x 1 1/2" x 1 1/2" sanitary tee with a 1 1/2" 45 street elbow toward the kitchen sink and then a 1 1/2" 90 long sweep to the lav sink. I have been through the code book but still I am not sure if I can do this or not according to code. I attached a picture (top view) to try to show what I want to do. The position of beams in the crawlspace drive me to propose this solution. Any advice would be greatly appreciated.