A scan told me I have a bad throttle sensor. Could it just be a loose wire and how can I find it?

Is that digital display for engine temperature or outside air temperature? A reading that low would typically be due to a temperature sensor is unplugged. Most cars used to use separate sensors for coolant temperature for the Engine Computer and dash gauge so if the one for the dash gauge was disconnected, it would not set a fault code or turn on the Check Engine light. Coolant temperature sensors are always on or close to the thermostat housing, usually at the engine end of the upper radiator hose.

If that display is for outside temperature, they often display "OC" for open circuit when they're unplugged. Those sensors are usually right behind the grille.