Hello everyone,
So this is the issue. I used to use Speed Fan for Voltage and Temp monitoring, and it showed a 125C under one of the CPU temperature meters. I was worried, but nothing seemed to be affected (the CPU was stable under Prime95 and it's water cooled, in addition to that, the core metrics were normal) so I ignored it.
I moved on to using Intel's XTU that is designated for my board (it's an Intel DX58SO2) which has 7 CPU temperature metrics; 1 for "cpu" and 1 for each core, all of which are normal.
Now, I need to use OCCT as I'm trying to push my GPU a bit more. I can't, because it is detecting the same stupid stealth sensor that I can't seem to find, and is aborting every test because it thinks the CPU is at 125C. I've posted an image below showing my metrics, apart from OCCT's. XTU shows just about all the temperatures there are to show, including IOH and Voltage regulator.
You can see the Speed Fan reading, on the right 5th from the top, that reads -27C. This jumps from here to 125C in a split-second. I've got not idea on how to deal with this.
EDIT: This is a link to the full-sized image http://postimage.org/image/z935w6cxl/full/
Also, the whole lot of sensors that read temperatures in the 90s on Speed Fan, I have no idea what those are.