Is your air mass meter OK? Keep it that way -- replace the air box thermostat (it's the small brass part pictured to the right). The thermostat lets preheated air into the air mass meter to help your motor warm up quickly when it's cold. When it fails, it lets hot air in all the time, which fries the air mass meter prematurely.
Air mass meter on the left, air box thermostat to the right |