Wall mounted oven getting too hot

I have a built in oven that is 18 years old and looks like its in great condition. I used to be able to cook a frozen pizza in 15 minutes as directed. Now the same kind of pizza burns in 8 minutes. It is a digital control panel. I need to know what parts I need and if it makes sense to try to repair. Thank you Dave

Hello. The first thing i would check is [part]AP2023670[/part] this should read any where from 1085 to 1100 ohms this can be done with a multi meter [part]AP3873826[/part] the sensor is what reads the temperature back to the clock and is your most likely problem thank you and good luck !