Looking for some advice to hopefuly save me some work... The 4 pipe stub seems pretty simple, drop a toilet on it. The 2 pipe in the rough-in I'm assuming would be for a sink or shower. Given the layout this is a bad spot for me and would like to put the sink (no shower) in the blue taped off area spelled out as 'area for sink'. I would rather not have to cut the concrete to use this 2 pipe if I can help it and thats where I am looking for some advice. I've been told as long as the sink pipe size is smaller than the toilet vent I can wet vent the sink into the toilet vent. This would save me quiet a bit of work. If I can do this then my next could questions would be... which pipe is the correct one to connect to 1, 2, or 3? I'm assuming 1 but I'm not even sure what pipe 3 would be so I'm really not sure... If I can connect to one of the pipes what do I do with the pipe in the rough in? Can I just cap, bury, and forget? Will it get full of stagnant water and cause odors somewhere in the bathroom or would the roof vent handle that? Any thoughts and advice would be most appreciated!