Hello to everyone, I am new to this forum and new to the duramax diesel. As of yesterday 10-28-2013, I bought a 2004 duramax with the LB7. Unfortunately I am already a little concerned, this vehicle has had all eight injectors replaced once, than last week before I bought it it had 4 of them replaced. So now I bought it yesterday and hop in it this morning and notice that it has excessive smoke at idle, but once I get going down the road it clears up, as soon as I get back to an idle it starts to smoke again. I really hope that its not injectors....any help or input would be greatly appreciated (note, I bought from a home town dealer, not an actual GM dealer)