Bossman36

Im having some issues with my 2010, was passing people and in the throttle and the check engine light came on and service exhaust system came on the dash. truck had like next to no power and was constantly
smoking like it was bogging out. got home cleared the codes and truck ran great again. then couple weeks later i was passing people again in the throttle pretty good and the check engine light came on then it said
on my screen on the dash, "service exhaust system see dealer now" got off the highway and stopped at a red light and the truck stalled out and wouldnt start it would just crank. getting a p0254 code and also had a p0193 code as well. bought a fuel rail pressure sensor and a plug for where the pressure relief valve was off amazon (probs not the best choice but it was 300$ cheaper) since ive replaced those the truck starts up now and runs rough still constantly smokes when test driven and sometimes it stalls when i stop and it will start back up also replaced the fuel filter. tried unplugging the FCA to see if it ran differently and didnt notice much of a difference. gonna
replace that and see what i get out of it. gonna have a scanner hooked up and see the pressure thats getting put to the rail and injectors.only getting the p0254 code now. ready to just take it to the shop and bite the bullet.

its a 2010 cummins, deleted with efi tune with a 5 position switch i run it on 5, intake, 4inch exhaust, built trans and put the upgraded head studs in it. any advice/input is really appreciated, thanks in advance.