Gas odor

I am getting a very strong odor of gas especially in the mornings and when I turn a corner on my way to work. In the afternoon there is no smell. I am not leaking gas, and when I asked the dealer they stated it was the catalytic converter. This started happening approximately six months ago. It is so strong that my fellow co-workers can smell it when they pull into the parking lot. One person mention something about a evaporator valve that may not be working.

Any help would be appreciated.

Mike