The statements from both Technicians A and B are correct.
Answer: Option C
Explanation:
A typical MAP sensors comprises with a ceramic or silicon wafers, sealed with an ideal vacuum on one side and a suction manifold on the other. When the engine (motor) vacuum varies, the differential pressure across the board changes the output voltage or frequency to the MAP sensor. So, sensor vacuum to be increased if injection pulse widths increase.
Most pressure sensors operate at 5 volts from a computer and return a signal (voltage or frequency) based on the pressure applied to the sensor (vacuum). When testing the MAP sensor, make sure that the vacuum hose and hose connections are tightly connected to the engine vacuum source. According to this, concluding that the statements from both technicians are correct.