So I did electrical work on my car, went for a test drive, and when I got home, had a knock. Using a pipe, I listened for the knock, and it seems to be from the injectors or the pressure regulator. Not sure if it's the pcv. It's not engine internal. Fuel injectors are still under warranty, so I may have to try a different set to see if the noise goes away. Any suggestions?

 

https://m.youtube.com/watch?v=ffCMaN_rNX8