Hey folks. I have a very foul odor coming from under the kitchen sink. I have traced it to the AAV. I tried replacing the AAV and still have the odor. I tried blocking off where the AAV screws in with duct tape and the oder went away. Any ideas what to look now? Does the AAV have an adjustment - couldn't find one. Finally, do I really need the AAV or can I just block it off? Thanks for the help!

AAV's should only admit air in and not sewer gas out. I don''t know what brand you're using but I recommend installing a Studor Vent.
By code every fixture that has a trap MUST be vented. A working AAV Does not expel air. If you have one that does then it's faulty. Good luck, Tom