wiring guys.. two pics of some things. Can ya help out?

[S13 240SX]

what is this? and if i pull the cap off its empty is there soppose to be something in there?



and is that plug needed its 2 wires 1 black and 1 white.

by the way this is rb20det too.

[Coolwhip]

first picture looks to be the Knock sensor plug.

[PorkChopExpress]

cant tell. since its currently 1:30 am i cant give you an answer right now, but i can look around my engine tomarrow and see if i can spot those plugs.

[kevwa]

i cant be 100% positive but i had 2 of them on my harness and before i wrapped it i traced them and came to the conclusion they were just diagnostic plugs - but i cant remember where i traced them to - anyway i pretty sure you dont need to do anything with them - if someone could confirm this that would be good

[Carl H]

neither are needed.1 wire plug with the cap goes to the aac valve for diagnostic testing to make sure it works and the other dead ends at a plug on the rb harness and is not used.