I smell gas!

I have a 2004 Subaru Forester and after slowing down after driving for a while there is a strong smell of gas. From the car… not my husband! I have taken it to the mechanic and he checked it all out and found nothing wrong or leaking. i had him change the gas filter anyway. We still have the smell.

Do you et a CEL on the dash after a gas fill up?

I’m thinking the EVAP system at the charcoal canister may be getting to the point of saturation and isn’t venting properly or perhaps the fuel regulator is leaking.
Your owners manual should show you the location.

Pull the vacuum hose free from the regulator and if fuel runs out, replace the regulator.

Is there no leak anywhere around the fuel system on the engine? Check this when the gas smell is the strongest.

Letting this go could be regretful.

In extreme cold weather, the fuel hose connections at the fuel rail in the engine compartment can seep. Usually tightening the clamps will remedy this.
Or check the fuel filler pipe in your right rear fender well / tire area. there is a plastic protective cover that holds road dirt, salt and moisture that will rust out the filler pipe.
If this is the cause, replace the pipe w/ a new one and discard the plastic shield.