Vehicle is 2017 Silverado 1500 5.3L-L83 6L80E.
Long story short here, looking for things in my tune that can be done to improve fuel economy some given the recent gas prices. I thought the O2 sensor setpoints might be a good place to gain a couple percent in fuel economy in the cruising areas without negatively impacting things too bad. Changed the O2 Sensor vs Airflow Mode table to 300 in the first 5 cells and sloping up to 450 in the last cell. Was all 450 across the board. Also adjusted the Min and Max Rich/Lean and Max Rich and Max Lean boxes accordingly. Or what I presume to be accordingly.
Drove it for a tank of gas to give things time to settle out and made a log on the drive home from work. To my amazement... things really haven't changed much and the average O2 sensor readings are nowhere near the setpoints. Maybe the changes I made don't do what I expected? Maybe the downstream O2 sensors have some effect on the fuel trims too?
I came to this conclusion by looking at the graph of O2 B1S1 and O2 B2S1 showing cell hits of 100 or more with the following filters to get steady state data only:
[50010.242]>180 and [50091.156]<70 and (abs([50090.156.slope(1500)])+abs([50090.156.slope(-500)]))<2 and ([4120.avg(1500)]-[4120.avg(-1500)])=0 and ([50091.156]<1 and [50020.114]>10)=0
Coolant Temp>180F, Accel Pedal<70%(to filter out PE), Throt Pos Chng<2%(to get steady state), Current Gear-Current Gear 1.5s prior(to filter out gear changes), Accel pedal NOT <1% and Vehicle Speed >10mph(to filter out idle and DFCO data)
I question the effect of the downstream sensor input because the cells where the downstream sensor is ~725mV or above, the average upstream sensor readings is much closer to the setpoints than the cells where the downstream sensor is below ~725mV.
So my questions are:
1) Does the downstream O2 sensor affect the fuel trims?
2) Is there anywhere to adjust the downstream O2 sensor setpoints?
3) Did I adjust the setpoints in a logical manner?
4) Is my data good and are my filters set up good?
5) What other areas of the tune should I look at for fuel economy?