first the only mds to the car are a k&n intake,shimmed wastegate,megan downpipe and catless 3' exhaust.Whats happening is when i'm driving down the road and let the car slow down WITHOUT pushing in the cluch or using the break(car doesn't do it if i press the clutch and or brake ) the car will smoke its whitish in color my first thought was bhg but i change the headgasket when i got the car(titan mhg and arp hardware).I'm not lossing coolent or oil as far as i can tell and the oil looks like it was just poored in and the car is pulling 20 vac anyone got any ideas? maybe the turbo