DTC P1128: Manifold Absolute Pressure Sensor Signal Lower Than Expected
WARNING: This page is about a different car, the 2003 Acura RSX. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition switch on. Using scan tool, check Manifold Absolute Pressure (MAP). If MAP is 16.0 in. Hg, 1.6 volt or more, problem is intermittent. System is okay at this time. If MAP is less than 16.0 in. Hg, 1.6 volt, replace MAP sensor.