I notice an odor in the cabinet underneath my bathroom sink. Any ideas what it is and what I should do about it

Does it smell like mold"" Could be a drip from the mixer or even the drain or trap. Remove everything from under the cabinet, wipe it down and cover with toilet paper, the best leak detector made. Back to you

It does not smell like mold
It has an awful smell and nothing is leaking

Smell like sewage?

Maybe it has a strong odor

Do you have an aav under the sink?

Yes

Hi all:

Mygirlsdad nailed it then... :) When an AAV fails it will allow sewer gas to enter into the home...

Unscrew the AAV and replace it with a new AAV... found at home depot, for sure!

While you are there, purchase some pipe dope, too and spread it on the threads of the AAV before installing it hand-tight or so.

Good luck!

MARK

Thank you

Please let us know how things work out.