I keep pulling 2 codes on a regular basis, p24ae and p2459.  After doing a forced regen they both come back within a few days.  I finally pulled the egr tube and the map sensor and both were really oily instead of having the gummy build up I've seen in all the YouTube videos. 
I also have a problem where if I'm doing a lot of city driving my exhaust will start to smoke heavily of and on. It will smoke the same way it does while doing a regen. I attached a pic for reference.
Truck isn't burning through coolant and doesn't appear to by burning through oil either. Am I having an oil blow by problem, or maybe something else?
			
			I also have a problem where if I'm doing a lot of city driving my exhaust will start to smoke heavily of and on. It will smoke the same way it does while doing a regen. I attached a pic for reference.
Truck isn't burning through coolant and doesn't appear to by burning through oil either. Am I having an oil blow by problem, or maybe something else?