New to the site. At wits end , 07 crd, green delete with hot tune. Worked amazing until I did oil cooler repairs. I repaired oil cooler, at same time glow plugs. Put everything back together and ect light blinks constantly. Only code was for glow plug 6. With my blue tech was able to clear code and runs fine, but light continues to blink, no other codes. Did this every start up for a month until the other evening I popped a fuel return line. Took the time and fixed glow plug 6 while reinstalling return line on injector 6. No codes at all at start up but light still flashing and now I can't get it out of limp. Take it to local general garage, there diesel tech looks at it today. Start up this morning in limp mode, scans it no code but runs clear on it anyway light still flashing but it runs great until it blows return line again. Runs full diagnostic on every system. Only thing found is slightly high pressure on injector 3. Clears no codes found, light still flashing runs great until return line pops again goes into limp. BUT NO CODES. I have read many posts with no clear answers with no codes.