What is the Manifold Absolute Pressure Sensor (MAP Sensor) all about?

In order to operate, your engine needs a combination of air, fuel and spark. Today’s engines are much more complex, and require sophisticated measuring of different elements to ensure proper fuel combustion. The manifold absolute pressure (MAP) sensor is responsible for some of these tasks.

Your MAP sensor measures the amount of air entering the manifold, the air temperature, and the number of revolutions in the engine. With this information, the car’s computer can adjust fuel and airflow to maximize performance while minimizing fuel consumption.

If your engine is not fuel injected, you probably do not have a MAP sensor. However, the vast majority of engines on the road today are fuel injected. For some automakers, the MAP sensor also serves a diagnostic function, allowing mechanics to analyze the performance of the EGR valve.

Keep in mind:

• The MAP sensor is an electronic component, and can fail unexpectedly.
• It is impossible to determine if the manifold absolute pressure sensor has failed with a visual inspection – it will require an experienced mechanic to diagnose the issue.
• A failing MAP sensor will trigger the Check Engine light.

How it's done:

• The vehicle hood is raised and supported
• The defective manifold absolute pressure sensor is removed
• The new manifold absolute pressure sensor is installed
• The computer is tested and codes cleared with a scanner
• The vehicle hood is closed and road tested for proper operation

Our recommendation:

While a failed MAP sensor won’t disable your car, it’s strongly recommended that you have it diagnosed and replaced as quickly as possible. Driving with a failing or failed MAP sensor can cause your engine to run “rich” or “lean” – that is, with either too much fuel, or too much air. Both of these conditions can damage the engine. However, there are many other conditions that can mimic a failed MAP sensor, including relatively minor vacuum leaks, so it’s important that one of our expert mechanics check the malfunction code and thoroughly inspect the engine.

What common symptoms indicate you may need to replace the Manifold Absolute Pressure Sensor (MAP Sensor)?

• Erratic or rough idling
• Delay in acceleration or deceleration
• Check Engine light is on
• Excess exhaust emissions resulting in failed emissions test

How important is this service?

Your engine’s MAP sensor is an important piece of technology, and should be replaced immediately to avoid potentially damaging your engine with lean or rich operating conditions and to ensure you’re able to pass your emissions test. If you notice any of the symptoms above, or your Check Engine light is on, have your vehicle diagnosed by one of our expert mechanics.