: I have a secondary, or cheater vent under my sink. whenever we do dishes or run the shower, anything that has alot of water going down the drain, there is a terrible smell that comes out of our sink cabinet. I have checked the piping and found no leaks, but sometimes there is a puddle in the sink base. Is my cheater vent leaking? The smell is deffinetley gas from my septic tank.

Nate,
It could be the cheater vent.
I would replace it and raise it higher, the line may be backing up and clogging it.