around frame 8718 im noticing low o2 numbers like you said. Also trims are locking in at around 0.8 at best.
Do a maf tune,
Set up a histrogram in the scanner and again do a maf tune from 7500 hrtz on down to 1500hrtz. This should get you're fuel trims back in line at cruise and WOT.
After you've done this i would probably like brian was getting at add 1% to the 7500 and up on the MAF table. When you go wot look at you're o2's. They should have come up into the 900 range. If not just keep doing increasements of .30 to the maf table 7500 and up.
After that has been taken care of it would be bennefictial to do a timing tune. Should already be set up in the scanner under something like ''main spark knock retard'' On the far right side of the table (wich should be wot subtract the amount you see there after you do a wot run from the main spark table high octane table. So if you have 2* of kr in the 4500 cell all the way to the right of the table take that much timing away from the spark table. Add 1 degree of timing to any cells that had zero in the far right of the table while scanning.
Keep doing this untill you maximize your timing.