Six Signs My Car Needs a New Oxygen Sensor

The oxygen (O2) sensor is located at the beginning of your automobile’s tailpipe. This sensor determines how much oxygen you have in your vehicle’s exhaust. It sends these readings to the engine control unit (ECU). The ECU adjusts the air and fuel mixture in the combustion chamber based, in part, on the O2 sensor’s readings. If your O2 sensor is going bad, York Tire & Auto Service warrants your car may experience one or more of the following symptoms.

1. Bad Gas Mileage

If the air and fuel mixture in the engine is off, your vehicle’s gas mileage will be reduced significantly. This reduction could be caused by too little fuel in the engine that is making it work harder. It can also be caused by too much fuel that the engine is burning away.

2. Black Exhaust Smoke

If the engine is burning off excess fuel, you will notice black exhaust smoke coming out of your tailpipe. If the O2 sensor readings are way off, the ECU may send so much gas to the combustion chamber that you’ll end up with flames or sparks coming out of the tailpipe.

3. Check Engine Warning

Any time the air and fuel mixture is not balanced properly, the ECU will turn on the check engine light. This dashboard warning light comes on any time there is something wrong with the engine that does not have a light of its own. A malfunctioning oxygen sensor will definitely trigger a check engine warning.

4. Engine Trouble

You may also notice that you are having engine problems. For example, your acceleration may be sluggish or nonresponsive or your engine may sputter and misfire. If there is too much gas in the engine, your engine may feel like a bucking bronco that surges forward even though you didn’t change your foot’s pressure on the accelerator.

5. Failed Emissions Test

Another problem with a malfunctioning oxygen sensor is that your vehicle will fail its emissions test. This could be due to the check engine warning, or it could be due to the fact that you have too much fuel in the engine and, thereby, too much carbon in your exhaust.

6. Rotten Egg Odor

Finally, any time there is a rich fuel mixture in your engine, the catalytic converter is inundated with gasoline. This can cause the converter to fail quickly and you will notice a rotten egg smell in your vehicle’s exhaust and/or coming from the engine.

York Tire & Auto Service in Red Lion, PA, would be happy to test your oxygen sensor to make sure that it is working. If it isn’t, we can replace it.

Photo by 3DFOX from Getty Images via Canva Pro

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