1989 Toyota Corolla Car seems to smell like gas vapors and

I have a 1989 Toyota corolla 4 door Automatic and i recently fixed the cataylic convertor on my car i seem to have to put gas in my car every 10 miles and i dont use it far just here in the neighborhood.It also smells like gas vapors,it also turns off when i back out and turn the wheel all the way to the left or right can anyone help me figure out what may be the problem i also changed the air fiter also.thanks