So while running my main feed line today, I noticed I'm missing the grommet that goes in the firewall behind the pcm. (Pic) I was wondering if anyone knows a place where I can get a new one, or if anyone knows something else I could put there? I think the open hole is also contributing to water leaking in while driving.

 

If you don't plan to go through that space for a while they sell a filler foam (that hardens) at home depot that you can spray on it, then paint it black.