This Preliminary Information communication provides information to the technician on the steps to diagnose and repair vehicles that may have a Service Engine Soon Malfunction Indicator Lamp on at low mileage. Technician may find Diagnostic Trouble Codes P0420 and or P0430 stored. Technician should be advised that the catalytic converter efficiency Diagnostic Trouble Codes P0420 and P0430 are disabled for the first hour of engine run time to allow break-in of the catalytic converter. Technician will need to use a Tech2 to check the verify engine run time on the Engine Hour Meter in the Instrument Panel Cluster Data Display/Data 1 List in the scan tool match. If the engine run time is less than one hour, the battery may have been disconnected, or another vehicle power loss event may have occurred, during vehicle manufacturing. Technician will need to clear the Diagnostic Trouble Codes and perform a drive cycle. If the catalytic converter was replaced and the Diagnostic Trouble Codes set it may be a result of the engine run time restrictions no longer being in place since the vehicle is no longer new. Technician will need to clear the Diagnostic Trouble Codes and perform a drive cycle.