Dual sink vanity conversion - drain advice

[dk4dk4]

Hi team,
I'm converting my single vanity to a dual sink vanity. I have opened the wall to expose the existing plumbing, which has both a 2" stack and 1.5" arm coming off for the existing single sink drain (blue line is flow direction). Where the red tuck tape is (existing drain) it does NOT tie back into the 2" stack (on right side of it)...

The green dots are the locations of the new dual vanity sinks...
Need advice please how to locate drains to the green dots. Do I have to get the 1.5" past the 2" stack going to the right? If so, not sure how to cross over the 2" stack, do I have to open the floor?

This is second story master bathroom. Inline with a main floor powder room bath, and basement bath...
Freestanding 2 story house.

As always, thanks in advance!

 

[Reach4]

You could insert a 2" x 2" x 1-1/2" DWV Reducing Vent Tee above the current vent tee. Use one or two banded flex couplers, such as Fernco 3000-22 or Mission CP-200. You would cut out a section of 2 inch pipe. You would glue the new tee in place. If you can displace the separated upper vent pipe to the side enough, I think you could get by with one banded coupler. Otherwise you will use two couplers to insert a section of pipe to fill the gap. If you cannot picture that, let us know.

You can probably get all the two-inch pipe you need from the piece that you cut out.

I am not a plumber.

 

[Sponsor]

 

[dk4dk4]

1. I don't see where the water drains in your solution on the right side?
2. This is an external wall and cutting 2-1/8 holes in 2x6 studs is probably against code (load bearing walls)...

What is proper today in this situation?

 

[Reach4]

1. I don't see where the water drains in your solution on the right side?

Oops.... that is a biggie.

 

[dk4dk4]

Anyone?