This is mounted between the main, in-line fuel pump and the hard lines ahead of the fuel tank. I thought it might be another pressure regulator of some sort. The larger diameter hose on one end is leaking and I didn't know if I could just run a section of hose without it. First it would help to know what it is. Second, if it turns out I do need it, can I source this whole section somewhere? I'm hoping the leak in the hose was causing a lean condition I've been chasing for a while. Any help is greatly appreciated. This is off my DD and I need to get it back on the road ASAP. It's times like these that remind me you need two old cars if you're going to have one...