What exactly is the function of the Pressure sensor. My check engine light blinks on at about 1/2 to3/4 throttle Then goes off. I pulled the code and it said pressure sensor. any ideas please.

 

A very important sensor for fuel delivery and ignition timing. At certain vacuum levels it may be putting out a signal that's out of the expected range for the ECU, which would throw a code. There should be a test for it in the FSM. If it fails, replace it.