So My wife drove all the way across the country and made it just fine but she said the car was a gas hog. I just bought the car and Im wondering if its the O2 sensors, but wouldnt that pop the engine light. Do you think the dealer unhooked it, and if so how do I hook it back up or check. The car has 100k now after the trip and all the fluids are good and the engine is strong. What else could cause bad gas mileage. The engine bay is super clean and it idles fine. Its a 95 GT auto.