sink sewer gas with p trap

Bought a house a 6 months ago and noticed that 1 of the bathroom's sink emits sewer gas odor when we use the sink. There is a p-trap installed and it appears to be installed correctly but i took a photo to show the experts. I have noticed that if we're gone for the weekend and then use the sink, the gas is worse than when it's used morning/night. Also, the sink drain doesn't have a stopper installed -- previous owner must have removed it. Any ideas would be appreciated.


p.s. yes, I asked the mermaid if she knew what was going on but she claimed ignorance.

-Kevin

It may be overflow in the lav that is the problem, the trap is fine. If it was a trap problem it would smell when it wasn't being used.

When you change the faucet be sure to change those angle stops, the risers are prone to cracking if wiggled. Tell that mermaid there is no swinging on the risers.

Hi tom, thanks for taking the time to answer. I feel stupid but I don't know what you mean by "overflow in the lav". Can you expand a bit?

The overflow is a drain hole in the upper section of your sink, that stops your sink from over flowing.

Sometimes a dry overflow will emit odor. Solution: pour some bleach in it.

Your trap might not be vented. Hence the trap is losing its seal do to air movement in piping system.