My truck had low fuel pressure codes and would go into limp mode on the hwy under the slightest load, the shop said the fuel rail needed to be replaced stating the pressure relief was opening too soon. I decided to do it myself with a complete Bosch OEM replacement which included pressure relief and pressure sensor. After install, truck ran great for about 20 miles to work. At lunch, as I was driving in the parking lot, it would misfire a little and was rough idle, and after about 3 more miles it started really running rough, wait to start light came and when I stopped the truck it stalled. I checked the codes and I had a P000F (high fuel rail pressure). If there was any debri in the fuel line, I would have assumed it would have shown up in the first 20 miles, and I was meticulous in keeping everything clean. I don't see any fuel leaking so was thinking one of the locking seals on the block might have loosened when I took off the injector fuel lines. Like I said, truck ran really great for the first 20'ish miles. I was thinking of removing all the fuel lines and ensure the locking collars on the block are tight, but I don't want to waste my time if there's a low probability it's the issue. Can you guys think of anything else that would cause this?

 

Figured it out, pressure sensor wasn't plugged in all the way and backed out.