Sort of. They are recurving the MAF, so the ECM thinks more (or maybe less) air is getting in. I'm not sure how this will work with a Toyota since TCCS uses feedback from the O2 sensor to provide an error correction factor. They have both long term and short term corrections, so unless they remap the MAF to something greater than 20% off, TCCS will just apply a correction to the a/f ratio to bring it back to the desired value.
This is one of the things that makes tuning Toyco ECMs with piggybacks very challenging. If you make adjustments to fuel in the closed loop maps, it just corrects to stoichiometric and applies the correction factor to all maps including the open loop maps, so there is no net gain. The trick it to apply changes so they only affect open loop maps (that's the only place you're going to see a gain anyway). Many Toyota tuners have complained about the ECM doing this because it forces them to be smarter than the ECM. Not a simple task.
One of the tricks is to adjust so the standard closed loop maps appear lean to the O2 sensor, which applies a rich correction to open loop. It's just tricky to get it right for best power.
