[neev_nav]

Failed o2 sensor could definately be the problem. Couple other things to check are coolant temperature sensor and the fuel pressure regulator. I have a 94 that ws running rich and it was because my fuel pressure regulator was totally rusted out and letting too much fuel in. But definately check those things out. If the coolant temp sensor is shot then it could be telling the computer that the motor is a lot colder out then it is and it is flooding gas in. Just some food for thought.