With any type of idle problem check the air ducts clean the IAC & throttle body Anti-lock problems if there is no hard code change the fluidClean the battery cables On pre OBD 2 vehicles unplug and plug in the PCM several timesCheck fluid levels for condition and quantityUse only the correct spark plug stick with the correct manufacturerDo the above before panicking about a problem. It will save on your blood pressure time an money