Did you guys ever resolve this issue ?
I had the same issue 2 weeks ago,took my car in for a service and the guys stripped the intake manifold off,the found a rubber gasket and some unit that had to be replaced,after that my fuel consumption is better,no more clouds of smoke at startup and no more noises or rough idle's.
I have the old parts at home,will take pictures and up load them and show you guys what they had to replace.