ok so about a week ago I pulled up a DTC(P0400) for an EGR problem. So I went ahead and replaced my EGR solenoid and cleared the code but the MIL light came right back after about 30 miles of driving. So I eventually came to the conclusion that maybe my Manifold Differential Pressure sensor was the problem because it wasn't keeping voltage when I raised the engine RPM. I bought a new one from the dealership and put it in, but the new sensor has the same problem as the old sensor did. I can't quite figure out why the sensor cannot keep voltage. someone please help!

 

oh and by the way its a 3.0 V6 Gasoline engine.