/sys is a virtual file system where you cannot store files. it is just for the communication with the kernel.
changing permissions on /sys is pointless. there were no changes on /sys in the different kernels version.

I have removed the remaining occurrences of "sudo" before commands in my tutorials - it was a mistake. sudo works only with specific commands but not with echo etc.

If you really want to use "sudo" with scripts, create a script which will run as root (i.e. no sudo in the script) and put an entry in /etc/suders.d so that can run the script using
"sudo script"