Oven Stops Heating

Question

I have a whirpool gold gas stove/oven. The oven will pre-heat fine and will stop heating and cooking. It seems like it just turns off. I've checked gas lines etc and all that is fine. Is it or could it ben be an oven temperature sensor? If so, is that something I can easily replace without having to call a technician? The unit is 4 years old.

Thanks