The side bars can come from several sources. If the signal is being broadcast with sidebars in the image then the TV is going to reproduce them because the TV sees that as a whole 16x9 image. If the signal is being broadcast as a 4x3 image to a decoder box such as a STB, Cable, or Satellite receiver, and if you have that unit set for a 16x9 monitor, then it will be the culprit for the gray bars and can be adjusted in its menu.