After getting a p2181 fault code in my car, I went ahead and changed out the coolant temperature sensor, and my reservoir(which had a leak in it), albeit those were both the cheaper options, the check engine light would stay off for awhile, but in the morning(when its coldest) the fault code always turns on, so I am now fully assuming it is the thermostat, since the car itself hasn't given me any over heating issues, perhaps it is stuck open, or reacting inefficiently. Is there anyone out there that can give me instructions, a tutorial, or a step by step breakdown on how to change the thermostat?