I didn’t feel like the factory solution was sufficient to prevent fire or carbon monoxide from penetrating through the firewall. So I created my own more airtight solution. All the wires going through the main hole, I did the following too…
I took all the wires and wrapped them in an extra wide zip tie. Standard zip ties are too small and I feel like it might pinch the wires. Then in the center where the zip tie would tighten up, I put red rtv in between the wires, so when I tighten the zip tie the RTV would squish out of the center of the wires. This whole zip tie contraption I positioned right in the hole of the firewall. Then I covered the rest of the zip tie in the red heat resistant rtv. It’s already pretty tight and almost filled up the entire hole. But I added a little extra rtv to seal the whole hole up completely. I then took more of the firewall, fire resistant, insulation and wrapped it around the wire attaching it to the firewall.
Sorry no pictures of this. My hands were too covered in RTV to use the camera.