[junktionfet]

The PAIR valve is misunderstood and it doesn't do what people think.

Underway and at operating temperature, the PAIR valve remains closed when the throttle is open... therefore the change you're feeling isn't due to your modification unless you're riding your bike aggressively before it has reached operating temperature.

There are no ill effects aside from increased cold engine emissions and perhaps a leaner mixture at idle when the engine is warmed up.

The PAIR valve remains open all the time when the engine is below operating temperature. The injection of fresh air into the exhaust stream oxidizes HC and CO emissions. That chemical reaction generates a lot of heat which brings the catalytic converter and O2 sensors to operating temperature faster.

When the engine has reached operating temperature, the PAIR valve is normally closed (no air injection), and only opens when the throttle is closed. This reduces HC and CO emissions while decelerating, and also offers a bump in the richness whilst idling--probably an effort to smooth out the idle. You can hear the PAIR valve close as soon as the throttle is opened--listen for a clunk or click as you slightly roll on the throttle from idle.

EDIT: BTW I have the same bike... Pearl White FTW :)