[elhigh]

The taller tires will probably help. It would feel less than fabulous to get new tires so soon after having just fitted these, though.

Warm air intake is your way forward, not CAI. Cold air = more mass flow into the engine, = more fuel capacity = more power. Warm air means less mass flow, less fuel, less power, requiring wider throttle openings to maintain the same power. Lower pumping losses.

Fire up the Hondata monitoring and see what AFR it's giving you. Will it permit lean burn? Can it be tweaked to do that? With the second O2 sensor it may not, and I think some of your fuel economy potential went away with that second O2 sensor.