How to Calibrate Your Air Fuel Ratio Meter

  • 2-3 hours
  • Advanced
  • 50-125
What You'll Need
12 v power supply
Digital multi meter
Digital infrared temperature gauge

If you need to calibrate your air fuel ratio meter to ensure that it is working properly in your vehicle, you can do the job at home rather than spend extra money on a professional. Calibration of the air fuel ratio meter should be done at least once a month for maintenance. You always want to make sure that it is working correctly to ensure that you do not have too much or too little air to fuel ratio going through your vehicle’s system.

Step 1 - Warming Up and Starting the Process

Warm up the digital infrared temperature gauge to 235 degrees Fahrenheit. This will allow you to get an accurate calibration reading. Hook the digital multi meter up to the 12v power supply. Make sure the fuel ratio meter is also hooked up accordingly. This will allow you to get an accurate reading. It can be done both in the vehicle and out of if the meter is not yet installed in the vehicle.

Step 2 - Calibrating the Meter

You can then hook the temperature gauge to the meter and power supply once it is heated up to the 235 degree temperature. You can then hit the calibrate button on the meter, or choose to hit the switch on the back to on depending on the model or make of meter you have in your vehicle. If you’re doing the reading out of the vehicle, then you should receive a max lean score because there is no fuel in the air. This means it is working how it should.

If your vehicle is on, the reading on the meter will be slightly higher because it detects the fuel. The reading might be lower if the engine has not stabilized once you hook it up. It should flatten out over time once the engine is warmed up.

Step 3 - Finishing the Process

Your meter should now be calibrated to the full extent. If you find that the meter is off by a few then you might want to consider returning it for defect and getting another. Make sure this one is calibrated to ensure that it will work once it is hooked up to your vehicle. Try to calibrate the meters before you place them on your vehicle, and then calibrate again once they are installed. This will give you a general idea of where the reading should be, and what to look out for as far as numbers go.

This method allows you to become the professional when reading the meter. You have the choice to find out how to do it yourself so you can do it whenever it is needed. You can also help other people calibrate their meters when they need it. This will save them money as well, and you do not have to worry about the job not getting done correctly since you’re the one doing it.