They say to unplug the maf when you do a VE tune.
Most of us don't do VE tuning at all/skip it.
Your fuel trims should lock in at 0 or close to 1 even if there is crappy weather. You are probably hitting parts of the MAF range that were untuned, due to either hitting PE and never disabling it during a maf tune or not a good enough scan to do the correct adjustments.
You want to start by disabling PE by setting the PE enable TPS to 100. After getting a GOOD scan, do your maf adjustments. I would do an adjustment, then reset fuel trims and do another scan and adjustment the next day. Either that or waste a lot of gas driving around through various throttle positions for 40 minutes with a few restarts in between.
After you've done this 2-5 times or however long it takes to get it damn near perfect, re-enable PE. Change the percents to something lower also, I think i have mine enabled at 20-25%. Either way, you want it lower than stock and it also helps to lock in fuel trims earlier, which sometimes helps it decide that it should lock in at 0 right ****in now.
As far as leaning the car out, you can either adjust the base PE afr then resetting the trims, or adjust it via maf table. Maybe subtract 3% from 8000hz on up or resort your scan by maf hz and see what areas need to be brought up or down. If you want richer, add. If you want leaner, subtract. Make sure to blend these adjustments so there are no jumps in the maf table either.
