Installing custom kernels on Android devices is very popular nowadays and there are plenty to choose from. A custom kernel offers a lot more customization than what a stock kernel offers.
You can do many things, change Android governors, overclock, change the voltage and many more! However, sometimes you change the kernel and flash a better one.
While this is good, in some cases the previous kernel leaves all the frequency and voltage settings intact.
This means that even though you installed another kernel, there will still be some leftover files and settings which you don’t want.
They are hidden very deep inside the system files and manually deleting them might be a little bit tricky.
But with a help of a tweak like Galaxy Kernel Cleaning Script these files can be deleted in seconds.
Along system and dalvik cache, this script also deletes any app which was being used by the previous kernel.
Download Galaxy S4 GT-I9500 Kernel Cleaning Script here.
It is a great tool if you don’t want to factory reset your phone and loose all your apps and data.