curious

my 2001 sl2 is idling fast at about 25 mph before i touch the gas,at a rest in park it idles fine but when i put it in gear it just goes on it's own. does anyone have a clue what i should look at to fix this problem?

my 2001 sl2 is idling fast at about 25 mph before i touch the gas,at a rest in park it idles fine but when i put it in gear it just goes on it's own. does anyone have a clue what i should look at to fix this problem?

Be more specific. Your post doesn't make sense. Engine speed is measured in RPM (big gauge on the right); not MPH (big gauge on the left)