First picture is the knock sensor plug in. The sensor is on the bottom of the block next to the oil pan. It does need to be hooked up.The second pic, showing a hose nipple , is the VENT for the solenoid it is hooked to. No hose goes on that.
IIRC that is the egr regulator solenoid.Be sure the hoses are hooked up correctly. If you cant find a vacuum schematic underhood, get one, or look at another truck with the same setup. It looks correct but I dont remember which port on the end with 2 ports is the correct port to go to the valve and which is the vent.
lastly I would perform an Intake air control calibration.
The procedure is easy.Check the other things first. Then move on to the IAC adjust. You will also need to verify engine timing before the IAC calibration can be performed.A timing light will be needed .
Fact is stranger than Fiction