[NicFromTheNorth]

Hi, I am looking for insight on some weird AFR Command behavior I observed in a data log. I recently installed a JDL 4-2-1 catless header, and flashed the OFT v4.03 Stage 2+ tune. The only changes I made to the rom file were in the drive-by-wire maps. My car is all stock, except for the header.

The data I show as an example in the figure is in closed loop, and the horizontal line on the MAF Voltage plot marks the LTFT switching from Range C to Range D (above 20 g/s). It looks to me like the AFR Command is somewhat erratic, which causes the STFT to chase a proper trim, and therefore causing the actual AFR to fluctuate too.

Does anyone have an idea on what is going on? Thanks for any help on this!