How to Trick A Mass Air Flow Sensor – Step By Step

The mass air flow sensor (MAF) is one of the most important parts of your car’s engine management system.

It measures how much air is coming into your engine and sends that information to your car’s computer to determine how much fuel it needs to inject into the cylinder.

You might notice poor gas mileage or overheating if this sensor doesn’t work properly.

Fortunately, there are ways to trick a MAF sensor into giving you accurate readings if its internal components have become damaged or corroded over time.

how to trick a mass air flow sensor

What is A Mass Air Flow Sensor?

A mass air flow sensor is a device that measures the amount of volume and density of the air getting drawn into your car engine.

It sends out a little signal that goes out to the car’s computer that says “you need to match this amount of fuel to this amount of air”. So that way your vehicle can run efficiently.

The accuracy of your mass air flow sensor is going to be critical to making sure that your engine runs properly. If for some reason your MAF sensor gets dirty in any way or even damaged, it’s going to cause an issue with the way your car runs.

Now, in most modern-day fuel-injected vehicles, they’re going to have a mass air flow sensor and it’s going to be located someplace close to the air filter – somewhere generally on the air intake system – which is the area where the air is going to get pulled into the engine from the air filter.

Generally, mass air flow sensors have different shapes and sizes depending on the vehicle. Some MAF sensors have an air temp sensor located within them.

So it’s kind of like a multi-sensor. But overall, they’re going to do the same basic thing which would be measuring the amount of volume and density of air getting drawn into the engine.

On the inside of the mass air flow sensor, there’s a little piton that comes up in the center. This piton is the actual measuring device.

How to Trick A Mass Air Flow Sensor

1. Get a Unique Tube

This tube should be at least 1 inch in diameter and 3 feet long. It must be in front of an ignition source (e.g., the engine).

The tube should have one end sealed with a rubber stopper or plug that’s been drilled out so that it can be heated by an electrical current passing through it. This will heat your tube and give the same reading as the fuel-air mixture coming from your car’s tailpipe.

2. Place The Tube in Front of An Ignition Source

The tube should be placed in front of an ignition source. If you place it on the side, it would be too cold and poorly functioning. You want to ensure you get a good amount of heat into the system.

If your vehicle does not have an electronic ignition system, use something else like a lighter or matchbook cover (remember: safety first).

3. The Tube Will Heat Up And Read The Same As The Fuel-Air Mixture From Your Car’s Tailpipe

This is the easiest method of tricking a mass air flow sensor. All you need to do is place a tube in your tailpipe and let it run up to your engine bay, where you can connect it to the mass airflow sensor.

Any type of copper tubing will work, but make sure it’s long enough (and strong enough) to reach up there.

Read: How to Clean Purge Solenoid Valve

What Happens If You Have A Bad Mass Air Flow Sensor?

If your mass air flow sensor isn’t working properly, it can cause a number of problems for your car. These include:

1. Damage to The Catalytic Converter

A bad mass air flow sensor can lead to excess carbon build-up on your catalytic converter. This means it cannot do its job properly and convert harmful emissions into less harmful ones before they’re released into the atmosphere. Because of this problem, the vehicle runs poorly.

2. An Oxidized Sensor Will Read Lower Than it Should

An oxidized sensor will read lower than it should, which in turn will cause the engine to run lean. This can be dangerous because an engine that burns too much fuel and does not have enough air is more likely to stall or have other problems.

On the other hand, if you trick a mass air flow sensor into thinking that there’s more oxygen in the exhaust than is present, your car will run rich (i.e., more fuel than it needs).

It’s also possible for a mass air flow sensor to get stuck on its own “best guess” value and fail to respond properly even when no one has tampered with it.

3. A Defective Mass Air Flow Sensor Will Cause The Engine to Run Lean

This means the engine is not getting enough fuel to operate at its optimal level. As a result, you may increase fuel consumption or have to add more gasoline than normal when refueling.

The process is very simple if you want to trick a mass air flow sensor (or MAF for short). The MAF is supposed to produce a signal representing the amount of air entering your engine when it reaches a certain temperature.

If the sensor is faulty, this number will be wrong and cause your car to run rich or lean.

If your car runs rich, you need more fuel than normal. In other words, too much fuel is being added into each combustion cycle so that unburned hydrocarbons and carbon monoxide are formed as byproducts of combustion instead of carbon dioxide and water vapor (which are both harmless).

This causes premature wear on many internal engine parts, including pistons, rings, valves, and cylinder heads, since they now have more chemicals, making them harder than normal under these conditions.

If left unchecked over time, enough damage will occur that replacement parts will become necessary.

4. A Faulty Mass Airflow Sensor Will Cause The Car To Run Rich

A faulty mass airflow sensor will cause the car to run lean. When this happens, the fuel-air mixture is your engine is using too rich, so too much fuel. This can lead to other problems that affect your vehicle’s performance and efficiency.

Engine hesitations and poor performance when driving are some of the major symptoms of a bad mass air flow sensor that indicate it’s time to replace them or carry out a maintenance.

What Is the Importance of a MAF Sensor?

The MAF sensor is an important part of a car’s emissions system, which measures the amount of air entering the engine. The ECU uses this information to calculate how much fuel should be injected into each combustion cycle.

If your car has been tuned using a MAF-based map, changing or removing the MAF sensor will throw off its calculations and result in poor performance and gas mileage.

Read: Engine Knock on Startup Then Goes Away

When Should You Bypass The Mass Air Flow Sensor?

There are lots of reasons why you might want to bypass the mass air flow sensor, but there are a couple that I will cover here.

First, when you need to know your engine’s correct air/fuel ratio (e.g., tuning a car for drag racing), the mass air flow sensor can be fooled into thinking that it’s getting more airflow than it is actually getting and thus incorrectly adjusting the fuel mixture (thus resulting in poor performance).

Bypassing this sensor allows you to get an accurate reading of how much oxygen is flowing through your intake manifold so that you can adjust accordingly.

Also, assuming your vehicle has been sitting all winter long without being started up once or twice each month over this time.

In that case, its MAF sensor has gone bad due to lack of use and time passing by without being used consistently. This often happens with cars parked outside during cold months without use.

Read: Drivetrain Malfunction BMW


A mass air flow sensor is essential to your car’s engine. Without it, your engine won’t be able to run at its optimal performance level.

However, this part can go wrong and cause it to stop working properly. Some of the ways to trick a mass air flow sensor – using a tube of one inch, then placing it in front of an ignition source.

After that, ensure that it heats up and reads the same as the fuel-air mixture from your car’s tailpipe.