P1129 HONDA Manifold Absolute Pressure Sensor Circuit Higher Than Expected

Possible causes
– Faulty Manifold Absolute Pressure Sensor
– Manifold Absolute Pressure Sensor harness is open or shorted
– Manifold Absolute Pressure Sensor circuit poor electrical connection
Tech description
There is a factory service bulletin for the following Honda models:

2001 Honda Odyssey
2003 Honda Odyssey
2003 Honda Pilot
Honda Factory Service Bulletin OBDII Code P1129

Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Engine hard to start
– Rough or erratic idle speed
P1129 HONDA OBD Code Description

The Manifold