2008 GMC Yukon Spark Advance question?

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New to tuning. I logged (attached) a little bit after turning p0133 and p0153 O2 switching codes off, after replacing leaking exhaust manifold with speed engineering shorty headers. I saw what looked to me to be some erratic and some aggressive timing changes. It doesn't seem normal to me, so I figured I'd ask here to see what y'all thought.

Forgot to add what it is. 2008 Yukon denali 6.2 L92 all stock except for shorty headers and plug wires. It does not have DOD.

The LTFT's are showing it to be lean throughout most of the part throttle rpm range.

It's definitely retarding the timing. You need to add a few things to your datalog in order to determine why. I'd start by adding knock retard to your PID list.

I hope you are using 91+ octane like you're suppose to as well.