Sorry, I'm new to this and don't know the ropes yet. I took my early 99 F250 SD PSD into a shop recommended by several different people and had an oil change done and he checked the truck over while doing that. Originally said that some other fluids needed changed, no big deal, and that 1 and 8 threw codes but wouldn't give me numbers. He said to bring it back in a week to see if the new oil helped with the issue and it threw codes for 1, 6 and 8. It has 161000 miles, so it was probably just o-rings, but as I didn't know the history of the truck and how it was treated...the oil was really overdue and the air filter was disgusting. So I decided to just do all 8 injectors and glow plugs. Drives better, was getting 12mpg, now up to about 14mpg so it's in the right direction, but it still feels like there is a miss and the turbo doesn't want to spool well until about 2200 rpm then just takes off like a bat. Took it back and he rescanned for me and this time threw 3 and 8. And by the way, I also cleaned out the EBP as it was clogged. What are my next steps? What should I do from here? Please help....I can do my own work, did the injectors and plugs myself and had no hydrolock or starting problems. Just don't know where to go from here. Thanks for your time and information.