I would like to add a new garage sink. The wall I am working on backs on to a bathroom with an existing sink. I can tap into the existing bathroom sink H&C water supply in the drywall. Can I also tap into the existing 1.5 inch PVC sink drain in the drywall (which runs horizontally draining to the main vent pipe a few feet away) by adding a T piece? I will definitely install a P trap under the new sink. Would this be the correct approach and code compliant?