The MAP sensor is used to convert the manifold pressure into an electrical signal for the ECU to use. The internal Manifold Absolute Pressure Sensor is a 3Bar sensor which is rated up to 200kPa of boost (2Bar / 29psi). Connect the sensor to the inlet manifold via the shortest possible length of vacuum hose and fasten with either hose clamps or nylon cable ties. Avoid connecting the vacuum hose below the level of the fuel injectors, because fuel may collect in the vacuum hose and run down into the sensor causing the sensor to read incorrectly or fail.