MAF Tuning, STFT vs WB variance Q

[epfatboy]

I set up my scanner to capture MAF Err using STFT's (default from HPTuner) and another using my WB (used hpt afr err math).

The diff between the 2 is significant in the lower hz range. The WB table keeps wanting me to add, the STFT's say we've had enough... and by the way it drives I believe the STFT's.

Why is that? I understand many folks like the WB just for WOT, but why is it that far off in the cruising ranges, might I have a problem or is there a specific area I should address only with the WB and only with the STFT's?

If it's a problem maybe some air is getting to the WB after the O2's? That feels like it would tell the WB it's leaner than it should be. It's a new exhaust with a Ball/Socket joint and a welded WB bung that are after the O2's, no noticeable leaks.

Last log attached.
short drive V5.1.7.hpl

[Alvin]

Because the car is intentionally switching lean with closed loop to hit the cats with o2. The average works out to be lean.

[epfatboy]

whoops, I should have mentioned I had set the tune up to scale the MAF. Standalone setup in C10.
CLOSE LOOP - off via ETC
MAF High RPM disable to 100
DEFCO off
COTS off
LTFT - off


This is the tune associated to the log above.
C10 Gen3 6.2 MAF V5.6.hpt

[epfatboy]

Just updating.

Reset to stock MAF Cal and restarted the tuning runs.
After the 3rd tuning drive in and applying the "* -1/2" from the STFT's everything is going the right direction
hz ranges I'm hitting on the reg are between 3375 - 6000
Percent err anywhere from 4.5 to 1 % as of this rev.
Noted that WB % variance similar to STFT % variance so far,
I think the WB starts to run away once the calibration table values are near 1% err reported by the STFT's.

Anyway good so far...