DIY MAF Resistors
A vehicle's mass airflow, or MAF, sensor monitors -- and reports to the engine's computer -- the amount of air the engine is taking in. This helps the engine correctly combine fuel and air for maximum efficiency. Some owners choose to enhance the performance of an MAF sensor by adding a certain resistor and potentiometer in line with it, customizing the air/fuel ratio to their liking.
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Things You'll Need
- Vehicle wiring schematic
- Digital multimeter
- Wire strippers
- Wire snips
- 47 kilo-ohm resistor
- 50 kilo-ohm potentiometer
- Soldering iron
- Lead-free solder
- Electrical tape
Instructions
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1
Locate the MAF sensor's signal wire on the vehicle schematic. Snip this wire near the MAF sensor. Strip 1/4 inch of the outer insulation from the computer side of the snipped wire, and clamp your multimeter's red alligator clip to this. Clamp the black clip to ground.
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2
Have an assistant rev the gas slightly. Monitor the voltage meter for increases in voltage as the motor increases in rpm. This tells you the sensor operates based on voltage, allowing the modification to proceed.
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3
Turn the car off, and remove the multimeter. Solder the signal wire on the MAF side to the left tab on the potentiometer.
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4
Solder the computer side of the signal wire to the center pin on the pot.
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5
Locate the MAF sensor's ground wire. Remove one millimeter of insulation from a section of the ground wire.
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6
Solder the resistor to the remaining tab on the potentiometer. Solder the other leg to the bare wire exposed on the ground wire, leading between the MAF sensor and computer.
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7
Wrap all connections with electrical tape. Mount the pot where you have easy access for quick adjustment.
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Tips & Warnings
If small adjustments make huge changes to air/fuel ratio, decrease the resistor and pot values. Remember, however, to keep the values of each as close together as possible, with the resistor being less than the pot, if necessary.
It is possible to bypass a MAF sensor with the right resistor. However, this places enormous strain on the oxygen sensors, causing them to fail prematurely. If your MAF continuously goes out, diagnose the issue instead of bypassing it entirely.
References
Resources
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