Recently invested in a built trans pretuned ecm from duramax tuner. I know enough to stay out of the high tunes without a built trans, but on the light tow tune (80 hp) the truck will respond with a bunch of white smoke when I floor it then turn to black. However, I don't think I'm losing power because the truck is much faster than stock. I also think this was an existing problem before efi live. The truck also blows excessive white smoke on cold starts. But it seems inconsistent. Sometimes it does it but then other times it won't even if it is colder. Anyone got any ideas?