Intermittent squeak/beep from engine bay
 

https://youtu.be/aREnC7bE1RQ

Does anybody know what this sound is? Just did new rotor/pads and an oil change. No leaks and oil level is just right.

I hear it when driving and when it's idle. After going out to bed brakes my car shut off by itself when I came to a stop in the garage so I'm worried about driving it.

EDIT: Car now sometimes fails to turn on and when it does, it dies immediately. CEL is on for system too lean. I reckon it's a vacuum leak.

So, what code(s) is the engine telling you?

It was P0171 system too lean. I kinda answered my own question and found an unstable connection with one of the hoses.