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What Happens to Sensors if They are Dirty?

dirty sensors

A Check Engine Light comes on and you know you need to add a quart. You back up and hear that familiar beeping noise letting you know you’re close to the car behind you. These actions are the result of sensors on your modern vehicle. Numerous sensors have been added to cars over the years to enhance the performance, efficiency, and safety of the car, but they have been around for years.

Early sensors

One of the primary sensors on a vehicle is the oxygen sensor. Each vehicle made today has at least one, and many have more than that. The sensor was first used in the late 1970s and was developed by the Robert Bosch Company.

Even before that, the wheel speed sensor was being developed. It was seen on the Chrysler Imperial in 1971. This sensor was part of the early ABS system.

Another sensor that’s been around for numerous decades is the throttle position sensor. It was added to engines in the later 1970s. Its purpose was to improve efficiency of the engines and helped replace the carburetor. The job of the throttle position sensor was to do what its name implies. It would determine the position of the throttle and alter the fuel intake to ensure optimal performance and efficiency.

While all of these early sensors are still in existence - along with many more - they have all changed and developed in answer to changing needs of cars and drivers.

If something’s malfunctioning on your vehicle and you take it to a mechanic, the first thing they'll look at the sensor that has an impact on the problem. Checking to make sure the sensor isn’t dirty is one of the least expensive repair options you have. A little dirt can cause a big problem.

The oxygen sensor

Cars today have at least one oxygen sensor, and they may have as many as four or five, depending on the model. These sensors are prone to getting dirty because their locations within the exhaust system. Their job is to monitor how much unburned fuel is present in the exhaust system. When they are dirty, they may provide inaccurate information, or none at all, which prevents the system from making needed changes in the fuel/air mixture. This will reduce the car's performance and the engine will have to work harder.

The MAP sensor

The manifold absolute pressure (MAP) sensor changes the voltage and frequency of the intake vacuum, depending on the air pressure in the manifold. When the sensor is dirty, it doesn't make the necessary changes, which slows down or speeds up the ignition timing. As a result, the car will hesitate when you try to accelerate or go up an incline. and has poor overall performance, even though it will continue to run.

The MAF sensor

The mass air flow (MAF) sensor measures the volume and density of airflow to tell the engine how much fuel must be added. When the sensor gets dust or dirt on it, incorrect information can be sent to the diagnostic computer. The wrong amount of fuel is added, which can lead to stalling, sputtering, and hesitation as well as loss of power or lower fuel efficiency.

The ABS sensor

The ABS sensor or wheel speed sensor helps you maintain control of your vehicle when you need to brake or when you are driving on slick pavement. If this sensor gets dirty, it can cause the ABS light to turn on, indicating a problem when none exists.

In general, sensors that work with the engine impact the performance when they get dirty. The engine may sound rough, not run as well, or have less efficiency or power. For instance, the oil pressure sensor tells you when the amount of oil is getting low. If it’s dirty, it may not respond and you could run out of oil and damage your engine. Many of the sensors will issue a trouble code to the computer. While the codes may not tell you there’s dirt on your sensor, cleaning them can eliminate one possible problem.

Keeping your sensors clean is important to ensure optimal performance and a long life for your vehicle.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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