MAP Sensors (Manifold Absolute Pressure Sensors) are used to provide the manifuld air pressure to the engine's ECU. This information is in turn used to meter the proper air/fuel mixture and potentially test the EGR system.
When MAP sensors fail the engine will not be able to properly meter the amount of fuel necessary to achieve optimum combustion. The mixture will either be too rich, which will cause unburnt fuel to be present in the exhaust, or too lean which will cause the engine to stutter upon acceleration.
Replacing a MAP sensor should be easy on most vehicles as it is located on top of the engine in the intake.
We stock and sell a wide variety of quality MAP sensors from these manufacturers: