I have a friend who's grandaughter has a 1992 Mitsubishi Galant that keeps tripping the following codes.
P1400- Manifold Differential Pressure Sensor, and
P1500- Generator FR Terminal Circuit Fault, now It sets these codes right when it goes into open loop at warm up, but it doesnt do it all the time the last time we reset the codes it took a month before it set it again.
we have done all the check per the book for the map sensor, there are no vacuume leaks between the MAF and MAP sensor, the alternator has been replaced we are just at a loss and im just wondering if anyone here has delt with this issue before or if you have any suggestions?