00' mazda 626 engine light

I have a problen with my engine light. I have been fighting it ever since i owned the car. It has said various things from O2 sensor to mass air flow sensor. I have changed all kinds of things. I have changed Fuel pump, Inlet air temp sensor, Mass air flow sensor, Coolant temp sensor, Idle air sensor, MAP sensor, Throttle position sensor, THE WHOLE THROTTLE BODDY. Fuel pressure regulator, Injector seals, Intake manifold gasket, Both O2 sensor's, and the catlyac converter. I have also ohmed out almost all of the other sensors that i could.

AND STILL ONE CODE COMES BACK (P1131) MANUFACTURER CONTROL FUEL AIR MEATERING
AND A CURRENT ONE (P1506) MANUFACTURER CONTROL VEHICLE SPEED IDLE SPEED


DOES ANYONE KNOW WHAT THESE MEAN OR CAN TELL ME HOW TO GET RID OF THESE?

THANKS FOR YOUR TIME.