Hi Aggro, in order for people to help you troubleshoot, you should give them as much information as possible. Start by giving the year, make, and engine of your truck. Any other information is also good, such as mileage and any work or upgrades that you have done. The only question I have at this point is have you changed the oil and fuel filter?
01 F-250 SD 7.3 POWERSTROKE SUPERCAB/LONGBED 146K MI, 3 gauge pillar, diy tymar intake, Edge Evolution Tuner, 26 row 6.0 trans cooler