I have a 93' LX 2.3. Sometimes, not very often, i'll be driving down the road and all of a sudden the pedal will drop all the way to the floor. I will have no power, so i immediately turn the car off, it then proceeds to back fire, most of the time with a ball of flames shooting out of the exhaust and a loud pop comes out with it. I then turn the car back on and then i works as if it has never happened. My friend did mention that my car was running a little rich the other day. He could smell it when he was behind me. I have no idea what is going on here so if someone could help me out.