Idle air control valve sticking. That will cause the throttle actuator to stay open.
When you put in the K&N Filters, did you oil them?
Because if you use too much oil, or dont let it dry out long enough before install, the filter oil will get sucked into the airbox.
The idle air valve (sits in the center) will suck the oil into the plunger, along with fine dust particles causing it to become sticky.
Same happens, if you do an oil change and fill too much oil into the bike.
The airbox will suck oil from engine case breather hose (far right hand) and contaminate the idle air valve with oil.
I would start of by removing the K&N filters and shove a rag into the airbox.... if its oily then you need to clean the idle air valve.