Initial code indicated replace bank 1 rear O2 sensor. When replaced, new code indicated problem with cat converter and same O2 sensor. I was advised that there was a TSB about incorrect error codes and I then had computer "reflashed" at Jeep dealer. Jeep dealer then advised error codes indicated problem with cat plus replace 4 O2 sensors (must be Mopar!) Meineke replaced cat with "strong" aftermarket unit plus 4 Mopar O2 sensors. Error code now indicates "cat deficiency". Feels like I am going in circles!