What does code P1128 mean on Honda vehicles?
The ECU detects that the manifold absolute pressure (MAP) signal is lower than expected.
OBD-II Code Honda
P1128 — Honda — MAP Lower Than Expected
The ECU detects that the manifold absolute pressure (MAP) signal is lower than expected.
Common symptoms
- Loss of power
- poor acceleration
Possible causes
- Vacuum leaks
- faulty MAP sensor
Initial recommendation
Inspect vacuum hoses and test MAP sensor operation.
Safety notice
This information is for guidance only. Brand-specific codes may vary by model, year, engine, transmission and vehicle configuration. It does not replace a physical inspection or diagnosis by a qualified mechanic. If the vehicle is unsafe to operate, avoid driving it and seek professional inspection.
Analyze this code with MecaOBD
Use the app to combine Honda code P1128 with your vehicle's actual symptoms for more complete diagnostic guidance.
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