Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P1129: Manifold Absolute Pressure (Map) Sensor Signal Higher Than Expected
Start engine. Hold engine speed at 3000 RPM with no load and transmission in Park or Neutral until radiator fan comes on, then allow engine to idle. Using scan tool, check Manifold Absolute Pressure (MAP). If MAP is 43.3 kPa (325 mm Hg, 12.8 in. Hg) or less, problem is intermittent. System is okay at this time. If MAP reading is not 43.3 kPa (325 mm Hg, 12.8 in. Hg) or less, replace MAP sensor.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.