The other day I put bad diesel in my powerstroke 6.0 and I noticed it was running like ****. It has an sct program and egr delete, 5 inch straight pipe and a blue spring mod with 6.4 banjo bolts. The truck when put to the floor barely makes it to 3000 rpm and sounds quieter. It has a good ficm on it and I think it has a clogged fuel filter but I don't want to replace it unless it is the problem because I replace them 2 months ago. Should I start with filters? I noticed less black smoke.

 

Turned out old turbo exhaust wheel was stuck in downpipe