So I have a 2009 6.4 and I just had the head gaskets and turbos replaced. My question is how long will it take to burn out all the junk sitting in my exhaust. It was at the shop sitting for a few weeks waiting to be operated on. I'm assuming oil had leaked into my exhaust system at some point during the failure. The truck smokes at long idles and occasionally when I accelerate. Anyone know if this is normal after the head gasket, head studs, and turbos replacement?