Ok, so I have no idea why I can't get into closed loop. I am also a novice tuner, so that is very likely to have an effect. I am well within my CTS range I set for closed loop (set it to -40c as a test) and my NBO2 sits around 450mV. Here is a link to a datalog and my bin (if you see anything crazy, please feel free to let me know). Also, I should mention, I have a cable driven speedo and the gear in the transfercase is currently broken so I don't know if that should/would have an effect. Right at the end when I park the car, it finally goes into closed loop until I tap the gas. However, I have also seen it temporarily go into closed loop while accelerating and decelerating.

datalog and bin here

 

I didn't look at the log, but most likely the O2 sensor isn't active enough.

and my NBO2 sits around 450mV.

For the O2 to be active the ECM needs to see it above or below the 'go into closed' loop region. Long tube headers require a 3-wire heated O2 sensor (AFS-74).

RBob.

 

Awesome! Thank you, have the sensor, will wire it in today!