Woops, I first posted this in the wrong place, but hey, I'm new here. Anyway, I just had the cat converter replaced, a tune up, and front and back o2 sensors changed, the front ones done twice. I thought the car was fixed until driving the other day and noticing the gas gauge visibly going down as i drove. After 20 miles I lost a quarter tank. That's really bad gas mileage. Anyone have a clue? Thanks.