Thanks for the reply. I am not noticing any vibration? It may be minor, I will pay closer attention. I have not changed the fuel filters since new so I am going to change them today with the oil and start adding cetane booster. I have been traveling a little lately and had to use a few small obscure fuel stops and suspected I may have got some poor fuel. I have burnt two tanks since the smoke problem and thought I ruled out bad fuel? I will check the codes today. I am making a 12 hour trip tomorrow and want to make sure no problems.