Why won’t my range oven maintain the desired temperature?

Does it lose heat altogether? Mine oven is never quite as hot as it says it is but it works fine. If it is loosing significant heat, see this article https://www.doityourself.com/stry/troubleshooting-an-oven-doesnt-maintain-temperature

How old is it?

Do you have the manual for your specific make and model of oven? Often they have troubleshooting sections, and it's hard to know what advice to give without knowing the type of oven, beyond the fact that it's gas. If you don't have a copy of your manual, try searching for one online. There are a lot of sites that aggregate household appliance manuals for free. Good luck!

I would google your year, make and model of your oven. Ask "How to fix Oven that won't hold temp for (insert oven type here.)

Get it serviced, my gas oven had a leak that the technician said could have blown up.... Gas shouldn't be messed around with. I never smelled any gas.

I would consult a professional repair person.

This is what I found

the temperature sensor inside the oven is not working as intended, it can cause the oven to not heat to the correct temperature. This can be caused by a faulty temperature sensor or a temperature sensor that is touching the wall of the oven.

Fix: Make sure the temperature sensor is not touching the inside wall, as this will affect its ability to accurately measure the internal temperature of the oven. If it is, reposition it so that it's not making contact with the wall. If it's still not heating correctly, you can use an ohmmeter to test that the sensor is working. The resistance of the sensor should rise with internal temperature of the oven. Like with a heating element or gas igniter, replacing the temperature sensor is a quick and easy fix you can do yourself.

Cause: If it's still not heating to the correct temperature and you've checked or replaced the heating elements, gas igniter and temperature sensor, it may simply need to be calibrated.

Go to https://www.repairclinic.com/ Enter the model number of the stove. They have repair guides, schematics and sell parts. If you don't repair it yourself at least you will have an idea of what the problem is so you don't get ripped off.

Sounds like the thermostat is gone you need a repair man to replace it.

Kathie...mine was the probe but also is an electric oven

Your thermostat may need recalibration or replacement. Call a repairman for this job since you are working with gas.