New Bathroom Drain Configuration

[DanMR]

I am working on adding a second floor bathroom. Due to space constraints, I am adding a new drain stack. I am struggling with that drain/vent configuration and was hoping to get some help. So far, the layout below is what i have come up with. I am not a plumber, so I may be way off. I definitely think there is an issue with what I have going on at the toilet fitting (I don't think that fitting even exists). If necessary, I can change over to a standard toilet, but am curious to see if there is any way to make the wall tank work. I am working with a 16" joist bay.

Any advice would be much appreciated. Applicable plumbing code is NSPC (NJ ed.)

 

[Terry]

The toilet comes off a wye fitting, not a santee on the horizontal. You can also wye off the vertical for the toilet. The lav and shower 2" would be enough to wet vent it the toilet.
I see the shower on a wye, that's good.
The lav should drop into a combo or wye fitting where it meets the horizontal. The santee is correct on the vertical.

 

[Sponsor]

 

[DanMR]

Thanks for the quick reply Terry. So if I understand correctly, I could something like shown below? That would make life much easier...

 

[Terry]

The last drawing works.