The basic function of a car’s air filter is to prevent harmful debris, dirt, and contaminants from entering your engine, but it also acts as a barrier to keep your MAF sensor clean. Many modern vehicles have a mass airflow sensor (MAF) located downstream of the engine’s air filter in the air intake hose. This sensor measures the amount of air entering the engine and communicates this to the ECU. With this information, the ECU can control how much fuel the engine needs for the proper air/fuel ratio.
The MAF sensor works by using sensitive hot wires to measure airflow, which means the smallest amount of dirt, oil, or dust can contaminate and/or damage the sensor. Not only will this decrease the longevity of the MAF sensor, but it can also cause inaccurate air measurement readings that could decrease the engine’s longevity as well.
Symptoms of a dirty filter
The air filter may be the MAF sensor’s first line of defense via the engine’s air intake system, but a clogged, low quality or dirty air filter can actually become the source of MAF sensor damage if any contamination bypasses it. Because of this, it is beneficial for your MAF sensor and your engine that the air filter stays clean. Also, avoid aftermarket “high performance” air filters that use a coating of oil on them. A visual inspection of the filter will show if it is dirty, but there are other signs when the engine is running that tells you if it needs to be replaced.
- A check engine light
- Poor fuel economy
- Loss of power
- Engine misfire
- Unusual engine noises
- Excessive black smoke from the tailpipe
How to change an air filter
As a common practice during oil changes, most technicians will inspect the air filter and ask if the customer would like a replacement. If an air filter is over its recommended mileage in the owner’s manual, it is best to replace it. If you drive frequently on dirt or gravel roads, you may need to replace the filter more frequently. If you elect to buy a filter from an auto parts store and save money by replacing it yourself, be sure to do the following;
*IAT= Intake Air Temperature
The Delphi Difference
When changing the air filter, take a moment to inspect the MAF sensor. If there are signs of damage or corrosion to the wires and/or connectors, consider replacing your MAF sensor for your engine’s performance and health. Delphi was the first OE Manufacturer to create an all-new, all-makes MAF sensor replacement option, meaning you won’t find any remanufactured MAF sensors in a Delphi box. Our MAF sensors are tested and calibrated to OE standards, ensuring the MAF sensor provides accurate readings for your vehicle's air-fuel ratio. Check out our catalog to see if we offer an all-new MAF sensor for your vehicle.
Questions about the cabin air filter? Check out this How-To article in our Resource Center.