Seems after first gear it hangs in second way too long to switch into third and accelerates terribly slow. Third gear seems to be the same way. It does eventually hit 60's (mph) it just doesn't like getting to that point. It also seems once it gets to a certain speed it rides comfortably. There is no over revving. It is just very hesitant.

Just checked and am receiving codes

P0402 EGR Flow Excessive
P0234 Engine Overboost Condition

What would be likely to cause these and what exactly am i looking at as far as repair possibilities and repair costs?