This is on the Valve Cover and it got lost while doing maintenance. Looked all over and pressure washed the motor hoping it would fall out. Any help is appreciated. The part number or name for the cover and the piece I am holding.

 

Unfortunately, that piece cannot be purchased separately, it’s part of the cam cover assembly:
https://www.ecstuning.com/b-genuine-...r/11127646554/

Maybe you can find one from a used parts supplier, like AllMag?
https://www.allmagautoparts.com