Ford focus idles at 4500 rpms?

I just bought the car. I have had the MAF sensor checked changed the TPS the throttle body is closed like it is suppose to be. Throttle cable is not caught anywhere. Air filter is clean. I just can't figure out what is causing it. Although I'm not too sure where all of the vacuum lines are but I'm working on that with the help of my chiltons book. Any input would be appreciated.