I have experienced similar poor mileage. I do know that one or both of the cats have been replaced under warranty at around 45k miles, I bought it at 54k and the original owner told me so. Ever since I own the car, I have not gotten more than 240 miles out of a tank before fill up of ~13.5 gals. I have noticed that the long term trim on bank 2 is running a bit lean at around 6 to 9% (some would consider this normal) and this could be contributing to my apparent poor mileage cause the PCM will open the injectors on bank 2 for a longer period to compensate for the additional air coming into the combustion chamber. So, I could have a leak somewhere around bank 2 and based on some of the postings, it could be around the head gaskets or lower intake close to one/two of the cylinders in bank 2. Not sure cause I have not taken anything apart yet. I need to take some time off to experiment with. But, I can tell you that I am also suffering from the emergency brake problems found in the FAQ. I lifted the rear of my car, spun the tires some and you can hear a slight drag as the tires slow down quickly. I have rear disk brakes and this is one of the conditions necessary to be a victim of this problem. I have bought the kit with replacement cables which I will do next week and then I will monitor the improvement gain to see the extent of the bank 2 lean operation condition on MPG. I offer this input cause there may be some similarity in what all of us are experiencing with these vehicles. Let us know what you find if you do more investigation in your case.
