Bad MAP Sensor Symptoms and Replacement Cost

Bad MAP Sensor Symptoms

If you are starting to notice something bad about your vehicle engine, one thing that technicians like me look into is the Manifold Absolute Pressure (MAP) sensor, along with some bad map sensor symptoms. The engine of your car will not operate unless fuel, air, and a spark combine together to create the ignition process. Modern vehicles, however, come with more complex engines, with the need to implement a sophisticated measurement of various elements in order to ensure appropriate combustion of fuel without damaging the engine unnecessarily. This is where the MAP sensor enters the picture.


7 Bad MAP Sensor Symptoms

The Manifold Absolute Pressure (MAP) sensor is a sensor in the engine of your vehicle, which measures the overall amount of air pressure that is present in the intake manifold of a vehicle. The pressure reading is utilized together with the engine speed in order to come up with the engine load. This enables the Engine Control Unit of the vehicle to deliver the accurate amount of fuel, which will match the volume of air that enters the engine.

What happens when a MAP sensor goes bad? There are signs of a bad MAP sensor, which will give technicians an idea of the problem. The consequence of a faulty MAP sensor, however, usually involves an inaccurate air-fuel mixture. The overall consequence still depends on the severity of the problem. It could be that the air-fuel mixture is too rich or lean. Here are some of the most common MAP sensor problems:

1. Excessively Rich Air Fuel Mixture

If the air-fuel mixture is identified as too rich, there are some symptoms that will be noticed. The spark plugs may foul, and it is usually accompanied by a faster build-up of carbon deposits. It is also possible for the catalytic converter to become clogged easily. Other symptoms include a strong gas smell from the exhaust, which means that the fuel economy will also suffer.

2. Lean Air Fuel Mix

This is the opposite of having a rich air fuel mixture. The consequences that are involved are often more serious. Since lean combustion is generally hotter, the life of the engine components could be shortened or damaged as a result of the excessive heat through time. This could also produce harmful emissions of nitrogen oxide and carbon monoxide. Another common consequence is predetonation, otherwise known as engine knock. If this occurs under load, it may result in a catastrophe, damaging the entire engine.

3. Misfires

If the ideal air fuel mix is already not balanced, there is a possibility that the engine will start to struggle just to maintain complete combustion. If this happens, misfires occur. At times, these misfires will also result in the throwing of their check engine lights.

4. Emissions Test Fails

If you are required to pass an emission test for your vehicle upon registration, MAP sensor problems will most likely result in a fail. This often comes as a result of an increase in the check engine light and noxious gasses.

5. Check Engine Light

For 1996 and newer models, your vehicle will have an OBD2 port. It may result in a check engine light if an issue with the MAP sensor is detected. One of the most common issues related to this symptom is DTC P0106 error code.

6. Hesitation, Stalling or Stumbling

The moment that you hit on the gas pedal or pull out while on traffic, among the things that you may notice if your vehicle engine is experiencing some bad MAP sensor problems include stalling, stumbling, hesitating, or an engine bog. When these happen, you may have an idea that something is wrong with the air fuel mix since there is a sudden influx of a lot of air, making it challenging for the engine to keep up with the sudden load requested.

7. Rough Idle

A rough idle could happen if there is an inaccuracy in the air fuel ratio. This can also result in excessive vibrations in the engine when in an idle state, or random jumps when going at idle speed.


MAP Sensor Replacement Cost

If you have already determined that there is something wrong with the MAP sensor of your engine, there is no need to worry. We are here to help you out. After all, the replacement cost for the MAP sensor should be simple and affordable. As a matter of fact, a lot of people can do it by themselves. Still, if you have not yet tried doing it yourself, asking for the help of experts is the better option to take.

The cost involved in the replacement of the Manifold Absolute Pressure (MAP) sensor could range between $70 and $240. This also covers the labor cost, which may range from $30 to $60. Though it does not look for the process of replacement, most auto shops have a fixed, minimum labor fee.  The cost to be expected for parts may also range between $40 and $180. These amounts exclude other fees and taxes, which you may also need to pay as well.

The process involved in replacement is quite fast. This sensor is just located right on, or just close to the intake manifold. This sensor is fastened down with a screw or clip. This means that taking it off is quite easy, and the replacement of a new sensor can also follow. The work of a technician involves checking the sensor, making sure that it is properly operating.


Last Words

If you start noticing the bad map sensor symptoms mentioned above, it may be time for you to consider replacing the MAP sensor of your vehicle’s engine. While it is actually possible to do it by yourself, given that it is a very simple job, asking for the assistance of a technician will ensure the quality of the job. After all, it may also need the expertise to determine the specific MAP sensor that is required for your vehicle. At times, the problems do not only involve the Manifold Absolute Pressure (MAP) sensor alone, which is why a thorough diagnosis may be needed to pinpoint the issue.


About the Author JamesL Davis

James is a certified auto technician specializing in commercial vehicles. With 30 years of experience under his belt, James has encountered almost every type of automotive issue there is! Besides his day job at the repair shop, he is also an amateur race car driver.

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