I hate to ask for help for something as simple as an O2 sensor problem but I am left with no other choice. So my car ran fine all last year until my fuel pump went. I let it sit for a few months until recently when I just got it back up and running. Now all of a sudden it decides to throw P0136 and P0141. Both codes pertain to the down stream O2 sensor in bank 1. So I replaced both down stream O2 sensors with used ones and cleared the code. Guess what? Yup, code came back. So I took it to a shop to have them scan and they told me the bank 1 sensor 2 was bad...ok I paid $40 to get told something I already knew. So I went and bought two brand new O2 sensors from Auto Zone. Installed them and guess what? Yup, code came back again. Decided to pull the trans wiring harness and check to see if its working properly. So I ran a test light to all 4 sensor connectors and they're all getting power. I finally got a hold of a friend's scanner and did an operational monitor on it. All the sensors are working fine except bank 1 sensor 2. It is staying at a constant 0.005 volts and not moving. There are no exhaust leaks and no vacuum leaks. The connections are clean. No frayed wires, nothing disconnected, nothing shorted, nothing exposed. The problem exists even when I run MIL elims. What could be the problem and what could be the solution? I'm thinking I should just switch the rear O2 sensor connectors with each other for a few seconds to determine if it's an O2 sensor or a trans wiring harness issue. Because if I switch the connectors, and suddenly Bank 2 sensor 2 starts having problems while bank 1 sensor 2 suddenly operates fine, then that'll tell me right there that the problem is with the harness. Any thoughts?