What sensor is this??

[permbayer]

Hey everyone just wondering exactly what sensor this is on my 96 4.0. It is connected to the egr valve via a vacuum line. I have reason to believe that the sensor is responsible for my po401 code. Any info is appreciated as I have seen conflicting reports about this sensor. Thank you.

 

[snoranger]

Thats not a sensor, its a vacuum solenoid. Its the EGR solenoid to be exact. When open, (signaled by the computer) it allows vacuum to flow to the EGR valve, thus opening it.

 

[permbayer]

Thanks for the quick reply. Could this be the cause of my code and bad gas mileage? Any wayto test the solenoid to be sure? I took it off and something is rattling around inside it.