my 06 is blowing blue smoke

[Hiteckredneck]

I have an 06 F350 with the 6.0. The only mods that I have done to the truck is a stage 2 AME cold air intake and 4"down pipe and 5" from transmission cross member back. I eliminated the cat. A few days ago I got on it pretty hard and every sense it has been blowing blue smoke a lot shortly after start driving.But the longer you drive it smokes less and less. It is not using any oil or antifreeze. I have been told that the 6.0 needs back pressure witch I have taken away. So I have been told I will probably need a tuner and or a custom tune. Anyone have any ideas?
Thanks
Rick