I have just finished installing a rebuilt engine for my 2007, 4.7 flex. The engine idle is running high at 1600. I have checked vacuum leaks, cleaned the throttle body, replaced the idle control valve, and finally just replaced the PCM. It still throws the code at start up. I have cleared the code after each replacement or possible fix. The one thing I keep coming back to is there some sort of vacuum issue. I made one mistake where I pulled some nicer hoses off a Durango at the junk yard and I got them mixed up. I have a inline PCV valve on the hose from left rear corner of engine block to the air filter (arrow pointing towards my air filter) My engine also has a PCV valve on the rt rear corner of the engine that is screwed into the block. If any one is an expert on Vacuum hoses I would greatly appreciate the help.