Mass air flow sensor (MAF) is important in car’s emissions system. The detector sends voltage to ECU, which manages fuel injection and ignition timing.
When MAF sensor is unplugged, ECU will not know the amount of airflow entering the vehicle with any accuracy. This leads to fuel economy issues and power loss in vehicles. In this article we are going to go through whether can you drive with the mass airflow meter unplugged, let’s jump straight to it.
What is Mass Air Flow Sensor (MAF)?
A mass airflow sensor is an instrument for measuring the rate of airflow into an internal combustion engine. It works by measuring the mass of air that flows past it and using this to calculate the actual flow rate. The actual design, construction, and method of operation of a MAF sensor vary considerably but all have the same purpose.
Can you drive with the Mass Airflow Sensor Unplugged?
In short, yes, you can. But you will lose the airflow information and will have a hard time maintaining the correct fuel ratio. You need to be aware that the car is not designed with no airflow meter, so it will run unsatisfactory.
The vehicle may require more frequent service intervals than indicated by the manufacturer. May also cause vehicles to fail emissions tests (if the state requires monitoring of MAF). This may also cause permanent damage to the engine computer and/or oxygen sensor.
What will happen if you drive with a Mass Airflow Meter Sensor unplugged?
If your MAF sensor is unplugged your engine is unlikely to get damaged so you shouldn’t worry about that but there are side effects of driving without plugging the airflow meter sensor including:
Poor Gas Mileage:
If you drive without the plugging of your MAF sensor, you’ll have poor gas mileage. The reason is that the ECU will always have to perform “calculations” to make sure it gets the right amount of air and fuel to inject into the engine. This involves a lot of time and is quite inefficient compared to just reading the MAF yourself.
Lower Power:
If you drive with the airflow sensor unplugged, your engine will be less powerful, again because the ECU will not have any accurate information on the amount of air that is going into the engine. This means it won’t inject enough fuel to burn all of this incoming air and so your car’s performance will suffer.
Engine jerking (Some Rare Instances):
The ECU will not know when the car needs to exceed certain limits and so it won’t know whether to rev up or go back down. This can cause your engine to suddenly jerk and make a weird noise as if something is going wrong with it. You’ll probably notice this when you get into your car each morning.
Rough Idle:
In some cases the idle of your vehicle will change when the MAF is unplugged, this is not something to be really concerned about; it’s just the way the ECU works and so when the MAF is unplugged, it will change how your engine idles. Some cars idle better when the MAF is unplugged though most do not.
ECU Air reading Damage:
In some rare cases, driving your car with the MAF unplugged can cause permanent damage to the Air reading ECU so if you want to be on the safe side, you can plug it back in. The number of people who have done this and damaged their vehicle is very low but it’s best to be cautious.
By far the biggest risk that you face by driving without a MAF sensor is one where you could be fined for tampering with emissions equipment. This can be quite an expensive fine in the US.
So, to summarize: driving with a mass airflow sensor unplugged will lower your fuel mileage, power and cause you to fail emissions testing. You may also damage your engine and possibly void your warranty. So yes: you can drive without the plugging of a MAF sensor but only if you don’t care about gas mileage and/or power.
Final Thoughts
n this article, we looked into whether is it safe to drive with a mass airflow meter unplugged and we’ve noticed that in fact, you can drive with the airflow sensor unplugged. But if you do so, you will be losing the information about airflow entering the engine and have a hard time balancing fuel ratios.
The result of driving without plugging the MAF sensor can lead to permanent damage to your engine computer and/or oxygen sensor. If you decide to drive with the MAF sensor unplugged, the side effects of doing so include poor gas mileage and power. Driving with the airflow meter unplugged can result in a fine for tampering with emissions equipment.
Robert Anderson is a world class motorhead who rebuilt his first carb at age 10, his first engine at age 15, and completed his first full hotrod build when he was just 18! Previously, he has ran a part warehouse, delivered pizzas, and managed the service department for a $20 million/year revenue dealership. Robert knows cars like few others and he is passionate about sharing his knowledge.