I have quite a few L3+
I installed a linux VM
Now if I understand corerectly, I first set the clock of the miner. let say 452mh
then I run the script and it will find the best voltage for it yes ?
Yes, that's right. You first set your desired freq and then let the script find the best voltage setting for each of the four chains in your L3+.
Could you post what you did exactly posting the exact commands you entered?
The "command not found" normally hints that you are missing the path to the command. I.e. if you are in the directory where l3plus_autotune.py is located, you need to add "./" in front of it to tell the shell that you want to execute the command in the same folder.
HTH