Hi dude. Thanks again for your excellent work. I am doing the mod right now as time permits. I have one plastic tube attached in the front rad support and will attach another in the airbox as soon as I can.
One curiousity....did you remove the "HC" screen just above the main filter?
Also, have you considered using one of the URD boxes to try reoptimizing the air fuel mixture? You might recall the fellow with the Forerunner who found that such mods tend to cause the engine controller to over richen the mixture, not necessarily due to sensor miscalibration you mention, but rather due to safety margin related behavior in the engine controller. He realized gains similar to yours when he installed a CAI, but found huge additional gains when he used a URD gizmo to lean out his mixture.