2000 Honda Prelude ObdII reads insuffient EGR flow/401

Check engine light on: I removed the Egr and shoved a coat hanger wire into the intake manifold approx 16 inches and scraped and the vacuumed the particles out. Also cleaned the existing Egr valve. No apparent excess carbon. And vacuum portion is confirmed working( also has electrical connector) also checked the Egr solenoid. Light still came on again. Then put on new Egr solenoid. Light came on. Put old egr sensor back on. Then installed new EGR valve. Cleared code and light came on again after 10 minutes driving. Dealer advised spraying "special cleaner" into the ports where Egr valve connects to loosen any carbon that may remain. Then blow into ports with compressed air. Engine will blow out any particles (if any) upon starting.I have not done the dealers recommendation yet. I have left the new EGR in place. What is my problem and solution?. As the light is still on.I don't want to remove intake manifold unless absolutely neccessary. By the way the car runs fine in spite of the check engine light. Any solutions? Help! Donation pending. I am considering looking at the MAP sensor next, based on some reading about egr's on this website. :Idea: