Originally Posted by art02gt
rear o2 sensors only monitor cat efficiency and have nothing to do with the engine running rich or lean. you have a rich condition which means you either have too much fuel or not enough air. I wouldn't throw parts at it yet, the first thing I would do is check for vacuum leaks (pcv hoses, intake gaskets etc.).
If I have a rich condition then why isnt the bank one sensor 1 showing a high reading. If both sensors are in the same gas stream then wouldnt they both have similiar readings.