Hi found this is something on servicing that gets easily overlooked. Positive Crankcase Ventilation valve is a one way valve to stop any increases in gas pressure in engine crankcase which may have crept past cylinders or valves. If not checked can cause sluggish running or at worst oil seal leaks. As Old Grizzly my CR-V has high miles and dribbles a bit i found the PCV partly blocked. Its situated on the top of the valve cover and held in with a grommet with a vent tube running off it. If you look on Google images/vid there are good pics. I disconnected tube, pulled gently from grommet and checked by shaking it should rattle which is good . If not, bad! Honda suggest at a certain miles replacement to avoid this but, as i am on a budget, i sprayed carb cleaner through and black gunge came out. I let it dry and replaced. Noticed smoother engine idle and less oil dribble from valve cover gasket which is my next task. This is common on other models not just CR-V so a simple job and worth a look.