When a Toyota engine works harder to drive up a hill, it needs a way to communicate within the engine to know how much fuel to use. A manifold absolute pressure (MAP) sensor plays a key role in this communication.
A Toyota MAP sensor is attached to the intake manifold. It senses air pressure brought into the engine for reporting to the engine's on-board computer. This information allows the engine to add or lessen the amount of fuel sent to the combustion chamber to control overall power.
Typically, a MAP sensor cannot be cleaned internally, since it is essentially a circuit board enclosed in plastic. But, the vacuum hose that connects to the MAP sensor can be cleaned out with canned air or a long stick. It is imperative the air supplied to the MAP sensor is not hindered by a clogged hose or the readings can be skewed.
Care must be taken while cleaning near a MAP sensor. Since it is an electronic component, proper electrical grounding procedures should be taken if working with the unit, for the safety of the person and the vehicle engine.