4 inch main stack to a kitchen sink drain

[yeyildiz0]

Hi

I am installing a kitchen sink by the wall and connect 4 4 1 1/2 wye or tee pipe to the 4 inch pipe in the image. Is this code?

 

[GReynolds929]

Is there anything draining from above? If yes you need a separate vent.

 

[MicEd69]

As that appears to be your main soil stack as there is a wye showing under the floor above, as GReynolds929 said, you need a separate vent. And you should indeed use a wye to connect to the 4". However, I would suggest using a 4x4x2 wye.