Off throttle false lean

[msassman]

I have noticed an issue while tuning that I have not seen addressed in here and was wondering if anyone else has seen this and how it has been addressed. If I tune idle while parked, I can get the values dialed in pretty good with both VE and MAF. If I am out driving and take my foot off the throttle while at high RPM, the higher airflow changes the values and the values show as lean, which causes me to adjust the values rich when multiplying by percent half, and this changes the values when idling while stopped. I have worked around this by tuning idle from about 1200 on down while standing still and filtering out below .5% throttle while driving to avoid the false readings. Where this becomes an issue if I don't compensate for it is when air density changes due to seasonal changes in temp, i.e., when the VE table moves up, the off-throttle values are now not in the off-throttle area and now in the cruising range. Is this normal or the result of me doing something incorrectly.

[Tunercharged]

I know what you mean, basically, to copy and paste error data from the entire error table you created will always cause you to lean out your tune in areas of deceleration. This shouldn’t be done this way. Tune for steady state airflow and use filters on the data and turn off transient formulas where possible to prevent other things than what you are tuning to change the AFR. I always tune in sections of g/cylinder airflow, I identify where I want to tune and then only change corresponding areas within MAF or VVE. I tune those separately as I easily forget what I’m doing, I’m no multitasker. I don’t worry about slight lean conditions on light throttle application but if I give it some gas I don’t want to see my lambda value ever above 1, even in partial throttle before PE is reached. I always run with a wide band and whenever I change anything I always test it to verify no knock or power loss. Using grams per cylinder tables in the scanner has really helped me tune things specifically.