DTC P1129: Manifold Absolute Pressure (Map) Sensor Higher Than Expected

Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Allow engine to idle. Check MAP sensor using scan tool. If 12.8 in. Hg or less, or 1.32 volts or less is indicated, problem is intermittent. System is okay at this time. If 12.8 in. Hg or less, or 1.32 volts or less is not indicated, replace MAP sensor.