I have a 2003 explorer with the 4.6 engine. It was stalling out on me when I released the gas pedal. I replaced the IAC value and it ran great for about 2 weeks. Then a loud humming noise started. It is coming from the air filter box. It doesn't do it when I'm driving just while I'm idle while in gear. But it will do make the noise sometimes while in park. Sometimes it stalls out too.