The boost sensor is located on the passenger side strut tower.  It is the small black plastic box with a vacuum fitting going into it.  The primary responsibility of the boost sensor is to read vacuum/boost levels from the engine and relay that information to the ECU.  The ECU adjusts ignition timing according to how much boost the engine is seeing.

If the boost sensor fails and trips an ECU error code, the ECU automatically defaults to a fixed setting (about 4psi).  The car will still run with a bad boost sensor.  If you still have your stock boost gauge, you can monitor that to see if the boost sensor is working correctly.

Questions?  Comments?  Send mail to: