I was referring to the fuel trims (adaptive learning) in my original post. That's why I said stft and ltft. Fuel trims are the correction being made to keep stoich, you have it backwards. What did you read?
There is no way your stft and ltft are only varying 1%.
The OP has all the signs of an improperly scaled maf xfer function. More than likely his tuner used the value file and left it. When the car was on the dyno the fuel tables were adjusted to get commanded lambda instead of fixing the maf xfer.
why would you say there is no way? on a highly modded car 6% is alot. and I know what you were saying to begin with. I agree with maf xfer being off, however, when the OP moves to closed loop I do not agree that stft and ltft should be as far out as 6%- that's just inefficient and lazy IMO. but then again I am constantly get my maf xfer table exact to the 10th decimal. that's just me.