Hi,

I have a problem in our kitchen where odor is coming from the drain pipe that the dishwasher and sink drains into... the drain pipe has an open end on it that vents directly into the space underneath the sink. Is this where I would simply install an AAV to the end of the pipe, assuming code allows this in my area? Or do I need to vent directly to the outside? Thank you in advance for any advice you can give!

Yes, AAV screws in, or should. At this point I would worry more about odor instead of code. "Open end" is a bit confusing, the AAV typically goes up from a Tee. Can you clarify exactly where the opening is?

The 1.5" pipe goes up from the tee and just ends... I think the AAV was supposed to go on the end of the pipe.It has been this way for many years... can't believe we only smell the odor occasionally . Thanks for replying!

With a connection to the main vent, you typically have a negative pressure in the lower pipes so no smell. Inversions and damp high humidity days can cause this issue. Is the top of the "T" threaded?