The CELs came back after a few drives and the next item on the list to address was the o2 sensor. And it worked! Many, many drive cycles and an hpde weekend and the smiles are back.
Before heading back to Road Atlanta, replaced the front rotors with another set of KNS, put Ferodo S13.12 pads all around, and bled with Castrol SRF. It was a long time since I did a track day and the first day with the OS Giken I felt like the rear would get wobbly and unstable in a couple corners, like the diff was redistributing torqe from one side to the other and back before deciding where to settle. Or maybe it was just getting used again to beating the shit out of the car and being smooth or the diff needed to be broken in properly. Whatever the case may be, on day two everything felt back to normal with no drama from the rear of the car. Both days were super hot so no new lap records. The hydraulic TOB kit worked and I guess I am now used to the way it feels.
Maybe now I can finally re-dyno the car with the front pipe and see if it makes any difference.
