I am trying to determine if I need to buy a new temp sensor or temperature control module.

The stove comes up to a temperature, then falls back 100 degrees before bake elements turn back on. It is typically 100 degrees below set temp.
Checked the resistance on the sensor and it is about .67 ohms at room temp and heating with a torch increases the resistance to over 1 ohm. I do not have specs on the sensor ohm range.
The control knob goes from 3.33ohms up to approximately 4.5 ohms.
Again I do not know the specifications

thankd for any insight. I know the stove is old, but everything functions except the oven temp