I have a 2006 Chevy tahoe. The engine light came on and I Had the OBD checked and came back with code p0454 Evap Emission control sensor Erratic. What should I do?

You've most likely experienced the Fuel Tank Pressure (FTP) sensor failure.
But scan tool failure records and direct diagnosis are needed to confirm this.
Have your Vehicle Identification Number (VIN) run by a local dealer, or some other source, to check for extended emissions related warranties that may apply to certain emissions system components, up to and including the PCM itself. Particularly, for a vehicle so new as an '06.