On my 500 mile trip home, I had to stop and fill up again, because I couldnt make it home on the one tank like I have for the same trip. My MPG was poor and I only had one bad sensor??? And you have two bad O2 sensors??? These folks arent steering you wrong. Your bad sensors are probably the most significant factor for your poor fuel economy. Of course as I'm writing this, I'm sure you've changed your sensors already. Just felt like reinforcing this info in case anyone else has concerns.