Is Your Engine Mixture Lean or Rich? Could Be a Faulty O2 Sensor

The modern-day car is a far more efficient device than its older cousin. It will not only return great mileage at the pump, but it will control its emissions very effectively. Yet as the owner, you need to do your part to ensure that such pollution is kept within check, and you need to take a closer look at one tiny part in particular. What is this component, and why is it so important to everyday operation?

Regulating the Mixture

A few decades ago, it became evident that cars and trucks were causing significant air quality issues and leading to severe pollution, especially in urban areas. Government regulators worked with automotive engineers to design systems to counteract this threat. Several solutions emerged, and one of these was an oxygen sensor that can fine-tune the air-to-fuel mixture within the engine to always be in its optimal range.

Lean or Rich?

As you probably know, an internal combustion engine relies on a controlled explosion. The fuel-to-air mix is ignited by a spark which causes a number of pistons to move up and down, turning the crankshaft and creating rotational drive. If there is too much air within that mix, this is known as being too 'lean.' This will give you inconsistent performance and could lead to significant damage. There are several reasons for this scenario, including low fuel pressure or a vacuum leak. Worryingly, this condition can lead to a rise in pollutants like nitrogen oxide.

If there is not enough air, possibly caused by a faulty ECU or bad injectors, then this is called being 'rich.' In this case, fuel will be left over after the combustion process, and this can cause an overburn, a buildup of deposits and a significant drop-off in fuel economy.

Sensor Issues

The oxygen sensor is supposed to check the amount of air coming into the combustion chamber. If there is an anomaly, it will immediately send a message to the ECU, which will adjust the mixture accordingly. However, given time, the oxygen sensor may become caked with byproducts of the combustion process. When it does so, it may be unable to perform correctly and could send inconsistent signals to the ECU. This could lead to additional problems, more money spent at the pump and decreasing performance. You may also find that your vehicle fails an emissions test.

Service Time

Avoid all these problems by taking the vehicle in for regular service. The mechanic will use tools to check the oxygen sensor's performance and clean and adjust as necessary. If you haven't had yours checked recently, take your car to a car service.