No, don't plug it or else the EGR won't work correctly. Chitty tapped a hole and put a fitting/drain hose on it. My only concern is that the oil is still leaking everywhere. I would have put a catch can on the hose or turned the hose into a "U" so that it's not leaking everywhere. Or you could buy a new EGR intake manifold and save yourself the trouble of cleaning it.