I bought an MDX and it had the check engine and VTM-4 lights on. P0401. I bought a new egr valve and I took apart the intake manifold. Cleaned all the little holes in the top of the manifold and cleaned the tubes going from the egr valve and the large tube going into the egr from the manifold. Cleaned the manifold really well too, it was really gummed up. I took carb cleaner and even a brush into the tube going into the egr from the manifold. The light still wont go away and I'm at my wits end here. Can someone please give me some guidance?