You might want to check under the right side of the cabin, as in underneath the passenger seat area just inside of the frame rail. There are a few breather lines there that return to the gas tank (not pressurized fuel lines, but I think they're there to help prevent vapor lock). I had a raw gas smell coming from there not too long ago in my 92 coupe, but it wasn't very strong and only on hotter days.
Those lines are not very robust, and can be cut by debris occasionally, or also by hitting the undercarriage while pulling a car onto a lift without due care. One of the lines was cut on my 92 coupe - I just clamped on a length of tubing and no more raw gas fumes ... which is not a good thing considering its proximity to the exhaust (!)
You might want to have somebody check the O2 sensor. I had a similar problem and discovered through a great mechanic that there was a problem with how the cams were set, also.