The oxygen sensor on your Toyota plays an essential role. You see, the oxygen sensor, also known as the lambda sensor, measures the oxygen content of the exhaust gases. The sensor feeds that information back to the engine control unit (ECU) to ensure that the engine is running at peak performance.

What Oxygen Sensors Do

Your vehicle has at least two oxygen sensors, and may have as many as four depending on the model, year, and engine. One sensor is located in front of the catalytic converter, while others are located in each exhaust manifold.

The upstream sensor monitors the engine's burning efficiency and sends that information back to the ECU. The ECU calculates the ideal air-to-fuel ratio needed to maintain both efficiency and power. The downstream sensor's readings are compared to the upstream sensor's readings.

If the readings are off, your ECU may trigger a diagnostic trouble code. If your oxygen sensor fails to function right, the ECU is forced to guess as to the proper fuel-to-air ratio needed. That can lead to a polluted engine, as well as cause trouble with your catalytic converter.

How to Spot a Failing Oxygen Sensor

It's not unheard of for an oxygen sensor to go bad. When that happens, you'll notice that your engine performance will begin to suffer. Signs of failure include:

Your fuel efficiency diminishes
The engine idles roughly
You notice the smell of rotten eggs
Your engine repeatedly stalls
You fail an emissions test
The "Check Engine" dash light comes on

If you’re experiencing any of these symptoms, test your oxygen sensors. If the results show that yours need replacing, do so as soon as possible. You'll also want to make sure that you choose the best ones for your vehicle. In your case, that would be the oxygen sensors made by Toyota. They are, after all, the only ones that are guaranteed to be compatible with your model. Find everything you need for the job right here in our online auto parts inventory, in stock and ready to ship. Buy now to save both time and money!