GAS SMELL IN EXHAUST

I have a 1997 chevy cavalier 2.2 liter with a 130,000 miles. My wife was driving and the engine light was flashing on and off. She had ran it out of gas one night and parked the car on a deep incline by the house in the mornining I put a couple of gallons of gas into the car. The car back fired 2times and a cloud of white smoke came out. As I check the exhuast pipe I smelled gas. I had my wife step on the gas peddal a little and noticed drops of gas coming out or the tail pipe. I turn the car off and checked underneath for gas leaks and found none. Also the check engine light stop flashing but now it stays on. The car manual says it may be an emission problem. But I have never heard of fuel leaking out of a tail pipe. I have not started the car since can any one help out I need this car to get back and forth to work.