my chevrolet tahoe wants to idle rough until it warms up and then youcan still feel it once in a whileen

Hello, a flashing check engine warning light is an indication of the engine's processor monitoring an engine misfire - where a cylinder or more than one is not firing as it should be. This is a sign of a concern that needs to be approached sooner than later, as a misfire can cause many further problems if you continue to drive the truck. Common causes are spark plugs or coils that are not working properly. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops