Well I sold my 06 5.9 and found a good deal on a 07 low mileage 6.7 dually just not sure I want a air purifier.

 

get the air purifier and do some altering to it. You will be happy with it.

 

Mine was an air purifier until last Saturday evening. Get the smarty and the deletes, it a whole different animal. I'm running the stock exhaust without the dpf and nox and its not much louder than stock which I like and I'm still running the stock tune. Initially I was VERY nervous about pulling the dpf and reprogramming, but I should have done that right after I bought the truck. Wow what an awesome vehicle, I can't stop driving it now and the grins are HUGE!!!!

 

did mine at 5,000 miles its a champ get that crap off instant 40 hp just doing exhaust you wont be disipointed