Been chasing down this problem for about a month now. Car idles fine, but has been hesitating while driving/reving. I changed my TPS, AFM, and ECU. While searching for any vacuum leaks I came across this item just hanging. It was in the area below the clutch slave. In the 1st photo I sat it on the filter, it is wired into the wiring harness. With the car running, it fluctuates voltage +/- 3V. Any help would be appreciated, I have no clue what it is or where this thing goes.

 

looks like a condenser or RF canceler.

i think its only purpose is so you cant hear your ignition in your speakers.

 

its supposed to go around one of the clutch slave bolts... its a ground of sorts

 

its the ground pack for the oil preasure sender. It bolts on the clutch slave cylinder. It doesn't do much, as mine is unhooked and my oil pressure is reading ok. Just bolt it up next time you get the chance.

 

Mine was hanging off like that too.

 

Hesitation: Have you checked your ECU grounds?

 

Thanks, I was worried for a minute. I will check the ECU grounds next, along with the O2 sensor wiring. I wish this problem came around before it strated getting cold. Oh well, the joys of owning an FC

 

That part basically smooths the signal going to the oil pressure gauge, and can protect the gauge from some sender failures/shorts. You should hook it back up, but I don't think its causing your other problems.