It's easy to check the PCV valve setup by checking if you pull a good vacuum through the valve when the engine is running. The original oil breather cap should be replaced with a cap that has a hose fitting on it, so you can run that hose off of the cap to a small filter installed in the air cleaner. This serves two purposes. If you have excess vapors they will be directed back to the air cleaner. If your PCV valve is pulling more vacuum than you have blowby, then it will pull filtered air back into your engine crankcase.