SO much bad information in here.......
Let me answer the question a little more eloquently. Does the MAF mod work with a CAI... the answer is Maybe. I would recommend first looking at your fuel trims with an OBDII reader to see how they are with the new intake. If they're not too crazy and out of wack, then the answer is yes, you could theoretically use the MAF mod. This is an assumption though, and your experience may vary.
The stock intake has a diameter of 2.5(I think it's something like 2.54, but my memory may be off). The MAF mod expects you to remove the veins and move the MAF up and out of the airflow. This will in term throws the AFR's way off and the fuel trims will be out of the expected range for proper open/closed loop fueling. to correct this, you would increase fueling by installing the yellow 330cc injectors from the 2zz with the expected results to have Long term fuel trims within +/-7 so that closedloop fueling can function properly.
Assuming your intake is the same diameter as the stock, that being 2.5", then it should theoretically mimic that of a stock intake with the veins removed. By then placing the PVC bit to raise the MAF, it should net similar results to a veinless stock intake. Adding the 330cc injectors should correct fuel trims at that point.
If anything, I would expect a proper CAI to perform better than stock, not because it flows more, because the stock can already flow plenty of air(it's been flow bench tested multiple times), but because of the velocity of the air being greater from less turbulence(long straight intake pipe), paired with cool air. Those paired with the MAF mod to increase timing should net maybe a hp or two? could potentially open up the top end a hair, but not likely and not much more than the stock MAF mod.