Inaccurate wideband readings according to commanded AFR?

[BigKID]

For the last week I have been trying to nail down the idle on my 370ci with 223/229 114+4 cam with futile results. Today I experimented with the commanded AFR control in the bi-directional scanner controls on a hunch that it was a little lean. My normal tune idle will surge between ~500-800rpm, 14.5-15.0 WB AFR, -0.02-0.02 lb/min STIT. When I turned on the control at 14.7 my wb jumped to 16 and really struggled on the idle. Gradually increasing the commanded afr consistently made the idle more stable. At a commanded 11.7 the WB showed 13.9 and the idle was rock solid. Even snapping the throttle open and closed it would fall perfectly back to the commanded 700rpm idle without any dipping or surging as it would with the normal tune. With the commanded 11.7 AFR all cells hit with the blips of throttle showed 13ish WB AFRs. Wideband is a PLX M300 w/LSU4.2 sensor permanently mounted in the truck and has been in there a couple years. Any one have any ideas or comments to the discrepancy?

edit.. forgot to say this is running OLSD. DFCO turned off.

[WS6FirebirdTA00]

yeah, tune your tables so your fueling matches up. Also, change to g/sec for idle airflow, you have no resolution with lb/min.

[BigKID]

yeah, tune your tables so your fueling matches up...

Can you expound on this statement? The only fueling table I have been messing with is VE and according to the WB histogram it averages 14.7 across the board. Should I be looking at another table to get the commanded AFR to match my WB readings?

btw.. thanks for the tip on changing the units on idle trims for better resolution. I had just been converting it to g/sec for RAF changes.

[99Hawkboy]

Use the VE AFR error % histogram to log the data and then copy and paste multiply % into your ve table to get as accurate as possible. Also change the decimal readings to 2 on both the editor and histogram for accuracy.

[WS6FirebirdTA00]

post a log and it will help us all from guessing.