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.
This article originally appeared on YourMechanic.com as What Happens to Sensors If They Are Dirty? and was authored by Joyce Morse.