2002 f150 4.6 motor had sever misfire, purchased new coils and plugs, and replaced. Removed battery wire for 30 min and reset codes. After starting motor idles extremely low. It almost sounds like I dropped and a cam in it, it just sits and loofs. It runs good and sounds good no misfire when on the open road, but almost stalls when you come to a stop. I did notice that when I removed the vacuum hose from EGR valve the engine idles fine, and runs fine. Could the EGR valve had failed, or is it linked to the plug and coil change.

Thanks for any help!!!!