Will a MAP Sensor Affect Gas Mileage?

by David McGuffin
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MAP (manifold absolute pressure) sensors are one of the many computerized accessories that help to ensure the proper firing and air-fuel mixture ratio of a vehicle's engine.


The MAP sensor helps to regulate and measure the pressure found within the air intake manifold, which is then sent to the engine's pistons for combustion. MAP sensors are crucial to helping the engine to reach maximum efficiency with gas mileage and aid the timing of the combustion process.

When MAP Sensors Fail

Failing MAP sensors will have a deleterious affect on an engine's fuel economy as well as other performance related areas such as horsepower and torque. Signs of a failed MAP sensor may include backfiring, occasional stalling-out and decreased ability to accelerate from a stopped position. The OBD II diagnostic check engine light will also turn on, indicating that the MAP sensor's circuit has failed.


Nearly all modern cars have MAP sensors, which also partner with other sensors such as oxygen, knock and the PCM (powertrain control module). It is important to know that a MAP sensor is not a component that can be added to an existing engine to improve fuel economy, but that it is already part of your engine, and without its proper functioning, your vehicle will display a decrease in miles per gallon.

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