I checked the air admittance valve and it was loose
. Took only 2 turns to unscrew it from the vent pipe. When I shake the valve is does "rattle" a little but it does not seem consistent. The rubber diaphram seems intact. It looks like an inexpensive part so I will buy a new one when I go to Lowes.
I just ordered a new toy; a 12 foot long usb "endiscope" waterproof camera
.... I want to "see" if the vent stack is connected to the tanks.
(Unfortunately it will take China 5 weeks to get me the camera....)
After that "exploration" I will fill the holes beneath the cabinet.
Hopefully the valve replacement will end the "stink".
Thanks for all the input.
2012 Dodge 3500, SLT Big Horn,CC,DRW,Cummins HO, EB, 4x4, 3:73, Retrax Pro, Q20, TST507, Garmin RV760, Sleek 4g
2014 Cedar Creek, 36CKTS, 640w Solar, TriStar MPPT 60, Magnum 2000w, PI EMS, WiFi Ranger Elite, Sleek 4g, Wingard DTV Traveler
Retired Army in 1995, and now retired in 2016