The mass airflow sensor is a key sensor in your car. Your car has a lot of sensors, and this is just one that helps your car run properly.
That brings up the question of can your car run without the mass air flow sensor?
In this article, we will look at what happens when you disconnect the mass airflow sensor. Read on to find out all you need to know about when you unplug your mass airflow sensor and if your car will stay running or not?
Before going into detail on what will happen when you disconnect the mass airflow sensor it is important to understand what it actually does. If you want a technical definition of how a mass airflow sensor works, then you can take a look at the article we have here, but for this article, we will just cover the basic function of the mass airflow sensor.
The basic purpose of the mass airflow sensor is to measure the amount of air that is going into the engine so your car can release the proper amount of gas into the engine, so the car is able to run correctly.
So, since the mass airflow sensor is used to measure air intake into the engine to keep the car running correctly, then what will happen if you unplug the sensor? Will the car die or stop running?
Well, the answer to that is no. If you disconnect the mass airflow sensor, then the car should keep running and still be able to start normally.
This is because the computer in the car if it does not receive a reading from the mass airflow sensor, will estimate and supply a number that it thinks it is supposed to have. This means that if your mass airflow sensor dies completely, then your car will stay running and surprisingly the car might run better without the mass airflow sensor. That is because if the sensor is bad or giving a wrong reading, then the cars guess might be closer to the actual amount of air that the engine is getting giving you a more accurate fuel mixture.
So, why might you want to disconnect the mass airflow sensor and drive around like that?
Well, the main reason is to test the mass airflow sensor and see if it is working right.
As has been mentioned by driving without it you might get better gas mileage and if that is the case, then it is a sign that you should clean or replace your mass airflow sensor because it is giving false readings.
On top of testing the mass airflow sensor by disconnecting it, you can also test some of your vehicles other sensors by disconnecting the mass airflow sensor.
If the car dies when you disconnect the mass airflow sensor, then that means it was working right and that your computer has issues.
It isn’t able to use the tables programmed in it to guess the amount of fuel needed. Also, if the computer isn’t the issue, then it means one of the other sensors is probably off if the car isn’t able to keep running without the mass airflow sensor because the sensor was helping the car compensate for the other issues that it was having. So as you can see disconnecting the mass airflow sensor is actually a good way to test a variety of things.
So, now that you know the reasons for unplugging the mass airflow sensor, the next question is when you should do it?
Well, the answer to that is pretty easy. Whenever your car is running rough, backfiring, or seeming to have issues with the fuel mixture, it is a good idea to unplug the mass airflow sensor. You can drive your car a bit and see if it runs correctly with the sensor disconnected.
If it does, then you know it was that sensor. If it doesn’t, then you know you need to look at one of the other sensors.
If it was the mass airflow sensor that is working improperly, then the first thing you should do to it is to clean it.
We have a guide here on how to clean it, but cleaning your mass airflow sensor is really easy and can help it start working correctly.If cleaning the mass airflow sensor does not fix the issues that it was having, then it is time to replace it. Sometimes mass airflow sensors get shorted or stop working and need to be replaced.
Once you have driven your car enough to test the mass airflow sensor it is a good idea to plug it back in or replace it after you are done testing. This is because it will help you get the best gas mileage possible.
That is because even though your car can run without the mass airflow sensor, you shouldn’t do it for long periods. That is because the numbers the computer generates are for brand new engines, and conditions change with the engine as it ages. By letting the mass airflow sensor make the readings, it allows for the most accurate numbers if it is working properly.
So, now you know what happens when you disconnect the mass airflow sensor. You know that your car will start and keep running even with the mass airflow sensor unplugged. In some cases, the vehicle might run even better if the mass airflow sensor is bad.
On top of knowing what happens though when you disconnect it, you also know why you might want to disconnect it and also when to disconnect it. You know unplugging your mass airflow sensor is a good way to test it and other sensors, but you also know that driving a bunch with it unplugged isn’t good because it gives more accurate readings than just your computer guessing at the airflow.
Now you know all you need to know about what will happen when you remove your mass airflow sensor from your vehicle.
We have changed the MAF on our Nissan Rogue 2011 twice this year as the tests kept indicating that was the issue. However, it is still stalling after a long drive and the engine light still comes up. I thought it could be an idling issue but every time we get the car tested, it keeps telling us its the MAF. What else can we do?
My Car Chery Tiggo 2014 model current mileage of 130K KM, MAF sensor isn't available in the market, and when I unplug the sensor the car runs absolutely fine, (I understand mileage can be off track) my question: Can I keep driving the car without the MAF sensor for next 10K-15K KM or maybe more? and what could get damaged eventually in the car if I run without MAF sensor?
I have a 1992 Subaru Legacy that idles rough and dies. I disconnected the MAF sensor and it started up and idled good for about 3 seconds then died. Is there another sensor that I need to look at. I have replaced the coil pack, spark plugs and the engine coolant temp sensor prior to looking at the AFM sensor. Thanks for any suggestions you might have.
Mike I just replaced my fuel injectors and keep getting a P0171 code, "Lean on Bank One".
These are refurbed injectors, not new.
I should mention that there is only one bank on my engine.
BTW, I am driving a 2006 Malibu LS, with the 2.2 Liter 4 -cylinder engine. 209,000+ miles.
I get NO other codes involving sensors, or the evap system.
So far I have changed the MAF, MAP, both Oxygen sensors, plugs, & the plug boots.
I don't think it's a spark issue, and I am leaning toward a smoke test to check for a vacuum leak.
Any suggestions ???
Thanks in advance for your reply.
What is the diagnosis if the car stays running after sensor is unplugged...Then cuts off after being plugged back up??
It doesnt mention check engine light will probably come on shortly after you disconnect it