One one other thing it may be , pop the hood look on the passenger side of the engine at the valve cover it may be leaking oil from the back corner closest to the firewall also check the small valve cover that's bolted on top of it it's about 6 inches long or so with a couple of bolts in it and a hose coming off of it, that is your positive crankcase ventilation cover and there's one on each side they are prone to leaking there is multiple threads here on the form explaining how to fix them, I believe that's what your problem is.