That code is for insufficient flow. There are basically 2 things that cause that on a Ford. One is the DPFE sensor which you have already replaced and the other is the passage through the intake gets plugged up with carbon. You can find this out by applying vacuum to the EGR at idle. If the engine doesn't try to stall, the passage is plugged. Sometimes yoy have to remove the throttle body to find the passage but it's in there somewhere.