WHAT SENSOR WILL I NEED IF IT IS BAD?

The sensor you will need for your model is linked below:

https://prismparts.com/products/for-kenmore-range-oven-temperature-sensor-pp5349693?_pos=1&_sid=d8e911a9b&_ss=r

The sensor should be roughly 1100 ohms at room temperature, if not it's bad. If the sensor is good the board is bad. The board for you model is linked below just in case:

https://prismparts.com/products/frigidaire-range-oven-control-board-pp6738426?_pos=1&_sid=2f4ccf98e&_ss=r