Here is a visual of what I'm working with (see attached). The shower drain is existing and so is the toilet. I'm adding the Lavatory line that joins into the shower drain after the trap.
Does the Lav need to be vented or is it wet-vented with the existing 2" abs that vents everything else? I could also run a line straight up from the lav area in the wall and connect to the 2" abs vent which runs horizontal above.
The lav is not vented and therefore the shower is not vented either.
The toilet is not vented with the right fittings.