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Can a Bad Map Sensor Cause Misfire? (Answered)

MAP or manifold absolute pressure sensor is essential for a car engine. It regulates the engine air pressure and controls the fuel burning. So, if your map sensor does not work correctly, can it cause a misfire? 

Here we will answer the question along with symptoms, solutions, and other information you may need.

Can a bad MAP sensor cause misfire?

A bad MAP sensor misjudged the necessary air and fuel needed for the engine and caused the wrong air and fuel ratio, leading to an engine misfire. A lousy MAP sensor also leads to delayed acceleration and more poor mileage than usual. However, some other issues can also cause engine misfire.

Are you facing random misfires while driving or starting your car? There is a possibility that the car’s MAP sensor is not working. Other problems like dirty car filters can also cause an engine misfire, but a broken MAP sensor is more likely to force the issue.

Let’s talk about how it works to understand the misfire problem better. In simple words, MAP sensors sense the volume of available air and ingest gasoline according to it. The available air volume can change depending on the place and altitude.

The engine needs a proper ratio of air and fuel to run as it should. The MAP sensor not only guides the engine to use gasoline but also helps to reduce fuel wastage.

But a faulty MAP sensor fails to calculate the proper air volume and necessary fuel. As a result, the car can act unusually and cause engine misfires. We will talk about the causes in detail in the next segment.

When the misfires occur, you can know by different signs. But it is more reliable when the engine indicator shows misfire codes. The display shows letters like P0301. The code means you have a one-cylinder misfire. 

A modern engine contains three, four, and sometimes eight cylinders, and it is hard to understand a one-cylinder misfire without an engine indicator reading.

A bad MAP sensor can affect your car’s overall performance and increase the fuel costs of your vehicle. So if you find any unusual behavior in your car, time to check the MAP sensor. 

A MAP sensor can work appropriately for 120000 miles to 150000 miles. If your vehicle is older, the MAP sensor can cause problems anytime.

How does a bad MAP sensor cause misfire?

A MAP sensor senses air volume and ingests gasoline accordingly. This sensing process is essential for the car to run without unusual issues. But what happens when it misjudges the air volume and necessary fuel because of a bad MAP sensor, and how does it cause a misfire?

When the MAP sensor is broken or outdated, it can not get the correct ratio of air and fuel. When the air is more than the fuel, it can not spark the cylinder and causes a misfire

If the MAP sensor indicates to spray more gasoline than air volume, that causes unburned fuel and random misfire as too much gasoline can stamp out the spark.

What are the symptoms of a bad MAP sensor?

Luckily, it’s easy to recognize faulty MAP sensors if you know what to keep in mind. Here is a list of symptoms of a bad MAP sensor. 

Increased fuel consumption:

If you find that your car is consuming more fuel than it should, a faulty MAP sensor can be responsible. Check the exhaust pipe if you notice increasing fuel consumption.

If the MAP sensor is causing the problem, you can find unusual smoke or smell from the pipe. This issue happens because the MAP sensor can not send the correct air pressure information and uses more fuel than usual.


A bad MAP sensor can cause a sudden backfire when the engine ingests more fuel than it can use. The remaining gasoline comes out from the exhaust pipe and sometimes backfires. If you are unlucky, even your car can catch fire.

Trouble starting the car:

If you often have a hard time starting Your car, that can result from a faulty MAP sensor. The engine needs the proper ratio of air and fuel to start. A bad MAP sensor delivers incorrect data about the air volume and necessary fuel for it. 

So the spark can not fire the engine.

Other problems can also cause this problem, but check the MAP sensor if you face this issue now and then, and everything seems right.

Performance problem:

A bad MAP sensor can cause a poor or rich mixture of fuel. Those issues reduce engine performance and show different unusual behavior. 

Rough idle:

When the MAP sensor does not work correctly, it can lead to insufficient fuel injection to the engine. That can cause sudden rough idle or low performance of your car.

Check the engine display:

Most modern cars have an engine control unit that regulates all the car’s sensors. It is an intelligent technology that informs you of any internal failure within the vehicle.

You can get information about MAP sensors on your car control unit display. If the computer finds any issue with the MAP sensor, It will let you know on display.

 Unusual sound and smell:

When the car engine has high or low fuel injection, it does not run correctly. As a result, you may hear unusual sounds while driving or starting.

If the engine can not use all the injected fuel, you may get an unburned gasoline smell.

How to test a MAP sensor?

Here we are including a step-by-step process of testing a MAP sensor. You may want to test your car’s MAP sensor if you find poor fuel economy, hesitation under load, rough idle, stalling, or starting problems.

Primary checkup:

The first step of testing a MAP sensor is a primary checkup. The MAP sensor is connected with a manifold with a rubber pipe. Any tube leakage can also cause problems in the functionality of a MAP sensor.

Look for visible faults:

Look for kinks, loose connections, swallowing, or cracks in the section. If everything is fine, you can start tasting the MAP sensor.

Start the integration key:

Now, start the integration key without turning on the engine. The car computer will supply electricity to the MAP sensor by starting the integration key.

Set a multimeter:

Then, set a multimeter to the MAP sensor. Set the multimeter in about 10V.

Check the reading:

The reading should be 5V or close to it. If the voltage is lower than 5V, the sensor wire or the PCM may be damaged. You will have to check the same wire at the computer site.

If that does not fix the problem, the car computer may have an issue.

If the voltage is correct, but the problem remains, the wire between the computer and sensor can cause it.

How to reset the MAP sensor?

You may want to reset your MAP sensor if it is not working correctly. Sometimes just resetting can fix the problem. Resetting a MAP sensor is a pretty straightforward process, and you can do it by yourself. Follow the steps to reset your MAP sensor,

Remove and check:

Remove the MAP sensor and check for any noticeable cracks or faults.


Clean the MAP sensor with dry air; also clean the part where the MAP sensor connects.

Turn on:

Put the MAP sensor on.

Disconnect the battery:

Now, disconnect the battery, leave it for 12 minutes, and connect the battery. Choose the hood and try to drive the car.

This process helps the car computer to relearn itself. If this does not work, visit a car workshop. 

How much to replace a MAP sensor?

You will need to spend about 60$ to 160$, including the service charge. The amount depends on your car’s model and MAP sensor quality. 

With some basic knowledge of cars, you can easily replace your MAP sensor yourself. You can find MPA sensors for 30$ to 100$ in car parts shop. It’s possible to save 30$ to 60$ by replacing it by yourself. 

Can I drive my car with a bad MAP sensor?

Driving with a faulty MAP sensor is possible, but you must not do it intentionally. Driving with a bad MAP sensor can be pretty uncomfortable as a lousy MAP sensor reduces engine performance.

Most importantly, driving with a bad MAP sensor can lead to further problems in your car parts.

However, if you find a bad MAP sensor on the road, driving to the nearby car workshop should be okay.

Final thoughts

A bad MAP sensor can cause various problems, including misfire. If your car often misfires, you should not ignore the issue as it can cause further issues in your car parts. Visit a car workshop to determine the problem. You can easily change the MAP sensor by following the proper steps.