Have an 05 escape xlt 3.0. When cold the engine cranks up and runs fine. Turn it off and back on it does fine. After it warms up you can turn it off and let it set a while and upon recranking it, it will stall at idle or run at 500 rpms. Keep giving it gas it runs fine and after a few minutes it will start to idle fine. Sounds like a rush of air when it finally starts to idle correctly. I replace the idle air control valve but still does the same thing. Codes are po511 and po446. Any ideas?