The MAF sensor is an excellent sensor that has found its way into many production vehicles, but it does have its drawbacks. It’s those drawbacks that I want to highlight, because they could be sapping power out of your ride. If you are interested in more details about how a MAF sensor works please reference the MAF article found under the technical articles section.
1) MAF sensor work more reliably when they are monitoring laminar flow across the hot-wire filament. If the filament is subject to turbulent flow, then the effectively calibration of the sensor is lost. Many aftermarket intakes can and often do alter the flow upstream of the MAF, and gains or losses can be due to slight changes in the effective calibration of the MAF (i.e. effectively changing fuel delivery), not necessarily volumetric flow rate improvements to the engine. You can minimize chances of turbulence near the MAF by eliminating flow transitions and bends within 12-18 inches of the MAF. Now this is not always practical in the confines of the engine bay. A compact alternative is a velocity stack positioned upstream of the MAF. This velocity stack will minimize the onset of turbulence and help maximize volumetric flow rates.
2) MAF sensors can get contaminated. Even with regular maintenance of your air filter, the hot wire filament will become soiled with dirt, oils, etc. With a soiled hot wire filament the air will not transfer as much heat away from the filament as it would have with a clean filament. So the soiled MAF sensor skews the signal that is used to determine fuel delivery to the engine, effectively resulting in rougher engine operation, and leaner fuel mixtures. Effectively robbing you and your car of power, which you are dumping your hard earned money to gain. That brings us to our next subject of cleaning your MAF Sensor.
This is a generic MAF Sensor cleaning procedure. You may wish to consult your service manual for proper removal and installation of your MAF Sensor.
1. Disconnect the battery ground cable.
2. Disconnect the electrical harness that is connected to the MAF Sensor.
3. Loosen any retaining clamps that hold the MAF to the intake system.
4. Remove any retaining bolts or nuts that hold the MAF to the intake system.
5. Remove the MAF.
6. Some MAF Sensors are equipped with a protective screen upstream of the filament. It is recommended that this be removed and cleaned separately. NOTE: Do NOT touch the filaments. They are delicate and will break/bend easily.
7. Gently clean the MAF Sensor by spraying carburetor cleaner or electrical cleaner onto the filament(s) in the sample tube where the filaments are housed.
8. I would recommend cleaning 2-3 times allowing the cleaner to penetrate several minutes between each cleaning.
9. Allow the cleaners to evaporate by letting the MAF Sensor dry effectively.
10. Reinstall the MAF Sensor by reversing the removal procedure.
11. Reconnect the battery ground cable
12. Start the engine to ensure the installation was successful. NOTE: You have restored the MAF Sensor output signal to its near original condition and depending on the severity of the change, your engine could run rough and poorly until the ECM has had a chance to “recalibrate” itself to the restored MAF Sensor signal output. It is recommended to find a procedure for resetting the ECM on your particular year, make and model of car.