ELI5: Explain Like I'm 5

Nitrogen oxide sensor

Do you know how you can smell different things like flowers or cookies or pizza? Our nose can smell different things because of tiny particles called molecules. Similarly, cars have a special part called the nitrogen oxide sensor that can smell certain molecules called nitrogen oxides that come out of the exhaust pipe.

When a car runs on gasoline, it makes many different things that go out of the exhaust pipe. One of those things is nitrogen oxide, which is made up of molecules of nitrogen and oxygen. Nitrogen oxide is not good for the air we breathe because it can cause pollution. The nitrogen oxide sensor in a car can smell the molecules of nitrogen oxide and tell the engine how much is coming out of the exhaust.

The engine then uses this information to make sure it is not making too much nitrogen oxide. If the engine makes too much nitrogen oxide, it means the car is not working properly. The nitrogen oxide sensor helps the car be healthier for the air we breathe.