Exaust Leak or Something Else?
 

It was dark so you can't see shit but this is the noise I'm hearing from the passenger side. Seems like it's coming from the cylinder closest to the firewall.

Had headers installed a few months ago so I'm hoping it's just an exhaust leak. :iono:

https://youtu.be/rVpovZVXK8o

It was hard to tell from the video. Would help if you gave it some revs. If it's an exhaust leak definitely replace it with a GM gasket and tighten it back down after a month to make sure no screws are backing out. I used the gaskets that came with the headers once years ago. Never again!

I did actually use new GM gaskets when they were installed.