Idle Problem

I have a 2011 Ranger 800, already checked the wires, and replaced the Tbap harness end, so the problem is, It starts fine idles fine, but after driving to switch gears it takes a few seconds sometimes to idle down so I can shift, also if I let it idle the rpms will creep up from 1250 to 1300 to 1400 and then taper back down and the cycle repeat itself. any ideas? just pulled all plugs and cleaned and applied di electric grease to them, they looked fine, checked the wires they also seem to be fine. also It is not throwing the check engine light on at all