p400 code

I have replaced the egr valve. The egr hoses look okay, the pcv valve and hose is ok. I have seafoamed the intake twice but the code keeps coming back I am stumped! What should my next troubleshooting step be

P0400 = EGR flow malfunction. The EGR gets exhaust flow from a port that runs from the driver's side of the exhaust manifold and through the head. This port through the head is plugged with carbon and needs cleaned. You can do this with a coat hanger, a wire, a spring on a drill, or whatever will clear that port.

If the EGR valve is off the car and you start it up, you should hear the exhaust leak from the now open port unless it's clogged of course ;)