98 ranger xlt 2.5 liter 4 cyl automatic. When cold it has a low idle and sometimes dies at stop light/sign. If I let it warm up for 10 minutes the idle remains low but it doesn't die at stop light/sign. Runs okay but not as good as it should. Have changed coil pack, air idle control, tuned up. CEL light is NOT on and it doesn't throw any codes either.