We established the fact that you have no rear o2 sensor in your last exhaust thread and that if you had no code for it then it likely had been tuned out...remember.
From the pictures you've posted I'm seeing two o2 sensors currently plugged/screwed in to your car, you have one in the stock location in the bung in the rear manifold and one in the downpipe.
Alot of turbo setups have the bung in the downpipe with the narrow band o2 connected there and have the stock bung in the rear exhaust manifold capped.
Did some one get lazy and leave a narrow band in there unplugged instead of capping the bung hole?
Guessing the o2 sensor in the downpipe is connected to the wiring harness and the one in the rear manifold is not?
Not sure what you have going on, can't see where any wiring is going with your close up pics.
Do you have the WB o2 sensor that came with the AEM kit that was with the car?
