Heavy gas smell

96 Bonny, 121k miles, all in all it runs great, get about 18-20 mpg city. Lately when I pull into my garage at night and turn off the engine I have a heavy lingering smell of gas. I cannot say if it in the exhaust when the engine is runing, and never thought to check, as I have not noticed any performance degredation or any check engine lights. No visible signs of leaks, no evidenc on the garage floor. Any suggestions?

Any Body??????