Originally Posted by daniel2229
The pipe running horizontally is the drain pipe from my wife's half of the bathroom sink upstairs. The vertical pipe running behind it is the drain pipe leading from my sink.
Why they were not united when the house was built is anybody's guess. All work done by licensed plumbers and passing building inspections, so what was I to know?
Thats interesting. That could mean one pipe is a vent and one is a drain. If they are both drains, and both vented. IF, if, if... They the might be able to be combined under the sink and the one in your way of removing the soffit removed entirely. Might...Cant say for sure from here.