Hey everyone, I am new to here and have a question about the way my truck is acting and was wondering if anyone could help. I bought a 2005 6.0 f250 with 115k miles back in february. I am no expert on diesels but it passed the eye test with flying colors. The engine was in great shape, no leaks, no blow by, drove well, etc. I've put 8k miles on it since (no towing) and in May it began having issues. I had the stock stereo upgraded and immediately filled up with fuel afterwords because I was low. As soon as I pulled out of the gas station and stopped at a light, it stalled when I hit the accelerator and then finally went, blowing out a bunch of black smoke when it did (that had never happened before). It did this a few times and then it stopped and everything was fine again, it was probably driving smoother than it ever had after this issue. I assumed it was a combination of dirty fuel and dirty fuel filters (which I had intended to replace but had not gotten around to yet). Everything was fine for the next 2 weeks until I was returning from the store with the right size socket to replace the filter. The truck was struggling to accelerate at low rpms and then died on me in the middle of the road after I had come to a stop and tried moving forward again (there was no smoke during any of this). It restarted fine and I drove it back and immediately changed the filters (they were nasty, dark brown color, honestly looked like theyd never been changed). I filled up with fuel again and dumped seafoam into the tank to help clean out the injectors. The new filters have less than 100 miles on them but the truck still seemed to struggle to move from a standstill when I was stopped at lights. It didnt seem right so I took it to a diesel shop and asked them to look over it. They said it was a bad EGR valve so I had it replaced. Just got it back but the problem doesnt seem gone. I also smell diesel when I'm at a standstill and I now have blow by when I previously had none, and when I say none I mean not a trace. I have no idea what the problem is or if there even is a problem and its just in my head. No check engine lights have gone off at any point throughout any of this and I dont have a code scanner but will probably buy one. Any help would be greatly appreciated.