I've erased and format everything, even removed the SD-card, fresh install of CM 12.1 and a few custom ROM that were reported as working nice with T-Kernel ≥10... not a change, it won't go over 1.4 Ghz. I'm trying to figure out what's causing this wild behavior, it might be the device subversion. So, please post your Xperia SP version and what's your case - it's your Tangerine (versions ≥10) allows for CPU frequencies over 1458 Mhz? Thank you!
C5303 14W07 TYPE: PM-0350-BV NOT WORKING