Before you put the broiler pan back into your newly cleaned oven, make sure the temperature sensor is accurate. Buy a portable oven thermometer and check it against the built-in thermometer in your oven.
You'll have to check the portable thermometer first to make sure it's accurate, though. There are two ways to do this. First, put the portable thermometer in boiling water and make sure it registers 212 degrees Fahrenheit. Or place it in water filled with ice cubes and verify that it reads 32 degrees Fahrenheit. You can use those temperatures as a baseline to establish the accuracy of the test thermometer you're using.
When you know the portable thermometer is accurate (or you can add or subtract from the readout based on your test), fire up your oven and measure the oven temperature against your portable thermometer. If you set the oven to 350 degrees Fahrenheit and the oven ready light signals that the temperature matches the portable, you're good to go. If there's a difference of, say, three degrees, you can adjust for it. On some ovens, you can even manually adjust the way the dial seats to recalibrate it to a correct setting. Otherwise, make the adjustment manually each time you cook.
This sounds like a hassle, but you only need to do it once a year or so. Calibrating your oven will help you be a better baker and save on energy, too.