here is what i would do since pulling the intake is going to be a biatch. i would remove the throttle plate. then i would removed the egr. then i would take a coat hanger or wire and run it into the egr passage and make sure that the wire went all the way into the intake manifold.. if it went all the way through, you will be able to see the wire from the opening were the throttle assembly was. try and do it this way first. removal of the manifold should be your last resort, but sometimes you have to. now, if the egr passage has curves in it, then you might have to use a thinner wire. make sure the passage is clear. if the passage is clear then your egr valve is defective remember that the function of the egr is to send exhaust gases back into the manifold, so the the design is pretty simple: egr valve opens and allows exhaust gas into manifold via egr passage in the manifold. for the system to work properly passage must be free of obstruction and valve must have free movment.