Yes, it could. Check the egr to make sure it isn't clogged with carbon as well as the intake where it is mounted. Also, make sure it is working (closing). If that is good, check fuel pressure drop off. When you shut the key, the pressure should maintain for a period of time. It is normal for it to drop off to 0 overnight, but shouldn't do it for a period of time. Also, pay attention to fuel pressure.