The sewer gasses are coming back up from a vapor leak somewhere in the waste line. In my experience as an amateur DIY'er it is most likely that the wax ring directly beneath the commode unit has failed and is allowing the gasses to come back up.
I replaced the wax seal yesterday and it made no difference. I even crawled under my home and examined the Plumbing underneath and everything was dry and completely odorless. It really has me stumped, the only thing that i haven't tried is replacing the commode. It is about 20 years old but appears to be in excellent shape.
Sounds like you have a water leak somewhere. It could be from a roof leak, or maybe an upstairs commode, or maybe a water pipe, in your wall, broke.
exhaust leak or fuel leak
You may want to check to see if the bolts are intact as well as the bowl itself.
Remove the commode and flooring. Dry it with a dehumidifier for a week and evaluate the damage.
Freon is odorless; you cannot smell it.
sounds like an exhaust leak, or a fuel leak. that depends on the smell.
As a piece of furniture, 'une commode' is a chest of drawers. As an adjective, commode means 'practical, easy to use'
A gas smell is usually caused by a leak. You should not drive the vehicle until the leak is repaired.
If you smell gas fumes you have a leak. To fix it you must find the leak. Your nose is your best tool to find the leak. This can be very dangerous so I would find and fix the leak ASAP.
There must be a gas leak. Contact your gas supplier IMMEDIATELY, if the smell is in a house. If it is in a car, have your mechanic check for a leak.
If you can smell gas it's very likely you have a leak somewhere. Even a small leak will produce noticeable fumes.
heater core leak