MAP Sensor Replacement
What is a map sensor?
The manifold absolute pressure (MAP) sensor, is located on or around the intake manifold, and provides constant information concerning the amount of pressure inside the intake manifold.
How does the map sensor work?
The engine's computer has to receive input from many sensors, and ensure they are in agreement. An extremely important sensor that is used in reference to nearly all engine operations is the manifold absolute pressure (MAP) sensor. The MAP sensor records the air pressure in the intake manifold, and reports that information to the computer. This allows the computer to calculate, or confirm, the amount of air moving into the engine, amount of exhaust gas to expect, the amount of fuel to send into the engine, and many other important factors. Lastly, this sensor works very closely with the mass airflow (MAF) sensor to allow extremely accurate response to changing conditions.
What are the symptoms related to a bad map sensor?
If the MAP sensor detects unexpected conditions, a few things happen. The engine's computer will trigger the check engine light, and the on-board diagnostic (OBD) trouble codes will reflect the air pressure conditions in the engine intake manifold. Also, depending on what pressure reading is present, the engine may compensate for these conditions, causing the engine to burn excessive amounts of fuel, sending black smoke from the exhaust pipe. In this case, the OBD trouble codes would also reference faults recognized by the exhaust oxygen sensors. The engine may also have issue with idling roughly, failing to start, stalling, hesitation, power loss, misfires, and fuel consumption.
»MORE: How to tell if you have a bad MAP sensor