The catalytic oxidation of CO under unsteady feed conditions was studied by infrared thermography on supported Rh and Pt catalysts and on a piece of metallic catalytic converter. On the Rh supported catalyst, self-sustained oscillations were suppressed by vibrating the feed which resulted in an increase in average conversion. Vibrating the feed decreased the ignition and extinction temperature thus extending the stable region of the high state for both catalysts. On the metallic converter piece, no oscillatory regime was observed under various conditions in which self-sustained oscillations are normally observed. Similar studies with 1% Pt/gamma-Alumina wafers indicate that the oscillatory behavior occurs when a region with a highly concentrated spot of Pt exists on the wafer. It is speculated that the communication between crystallites plays an important role in the synchronization of oscillations.