Venting a toilet in the Wall behind the toilet but the drain is across the room?

[Weekend DYI]

Can anyone tell me if I can add a vent only behind the Toilet and use a 3" ABS Sweeping 90 TEE to do so? The actual drain is 9 feet away across the room. See my attached Drawing.

[hj]

Your question is confusing. The pipe going up the wall behind the toilet is its vent. The other pipe will only be a legal vent if your inspector would approve it. Some would, but many would not.

[Weekend DYI]

So you are saying to vent behind the toilet like this is ok, even though to do it, I have to tee at the toilet flange?

[cacher_chick]

Your picture is not clear as to how exactly you plan to make the connection.

The vent cannot run horizontally behind the toilet so a tee would not work. A wye would work, depending on exactly how the connections are made.