Visual studio Code maxs out my CPUs even when its just open
High CPU is caused most probably by some VS Code extensions. Try running VS Code with all extensions disabled and check if You still experience such CPU.
From my experience the Import Cost extension can cause quite high CPU load..

If the CPU is allright with extensions disabled try enabling it one-by-one (work a little bit between enabling every next one) and try to locate which extension is a real CPU eater.

Here is a very good article about troubleshooting performance issues with VS Code: 
https://github.com/Microsoft/vscode/wiki/Performance-Issues

Good luck!