I have a soffit running under the bathroom ceiling upstairs in my 2 story home. It runs the width of the bathroom, directly above the sink, and comes away from the wall approximately 16" inches. There is one high hat in the soffit, directly over the sink.

I am remodeling the bathroom, and we wanted to get rid of the soffit & have one continuous ceiling height for the entire room. However, when I made an exploratory hole, I saw a 4" copper vent pipe running through the soffit.

It appears that the vent runs vertically up through the wall, then comes out of the wall into the soffit via a 45 degree bend. It then runs up into the attic & out through the roof.

How can I re-reoute this vent? The top plate for the wall is only a 2x4, so if I put the vent through the top plate, I would be cutting the top plate through to accommodate the 4" vent.

Is there a way to split this into two smaller vents, up through the top plate, then rejoin them in the attic?

I'd hate to have to keep this huge soffit just for one little 45 deg bend in this 4" pipe.

Thanks in advance.