Originally Posted by
ron's power stroke
electronic "do-dads". a number of these were replaced due to their effect on low speed, low boost drivability. don't mess with the electronics, the PCM and MAP Sensor maintain 100% normal connectivity with no electronic interference withthe OBA..the OBA lets the map see live ###''s at that moment.. the resistor is slow to re act..
Ron- the OBA keeps the MAP from seeing boost over 23 psi (or wherever you have it set). The diode does the same thing, only by limiting voltage instead of psi. I can see where the diode could effect the sensor in other ways (I'm no electronics expert) or may be slower to react but all it does is limit the voltage the MAP sends to the PCM.
Ifthe diode has no other effects on the MAP sensor I think it's a way better option than an OBA- less clutter, less cost. I really wish I could find the one I had...