I own an 03 f250 6.0l with 213k miles. I had a new bulletproof egr cooler and oil cooler, and injectors 1,5,8 installed shortly after I bought it at 208k miles. I didnt have the money at the time to stud it and wish I would have. I later ended up doing the remaining injectors after I had a # 4 fail. I had a p0263 code that kept coming back and the diesel shop replaced it 2 more times to try and fix it since nothing showed up in tests. I found a similar event on another members post where he mentioned the oil rail check valve. I ordered 2 new ones and replaced both sides. The p0263 hasnt returned but now it seems the issue I'm having is a reoccurring p0278 code. The strange part is, like the p0263 I was getting, it only happens when my truck is idling at a light and the ect gets to 154-158*. Its pretty precise. I only notice a slight change in idle smoothness and pull the codes with the edge cts2. I've been to my normal diesel shop that's done all the work, to Ford dealer, and made several calls to other shops. Nobody else seems to have come across this. All new injectors, new ficm, new wire harnesses(injector and engine), s&b intake, running Rotella t6 and use cetane additive with every fill up. I've ruled out tune, as it does it in stock mode. Now I'm unplugging Edge monitor all together. I dont know where else to go with this.