I have a 98 ranger 4x4 ,when i stop at stop signs and lights my rpms go up and it takes a while to come down,i have replaced plugs ,wires egr solenoid and it still does this please why does it do this .. Thanks michael

 

Idle air control valves (IAC) and Mass Air Flow sensors can give the results you are getting. Before spending a lot of money on guesses, see if there are any codes in the computer that might direct you to the problem of which system is malfunctioning.
Some auto supply stores will check this for free one of which is Autozone. There are some others, but I don't know which ones are in your area.