I just installed a Magnaflow Turbo back with an SCT X3 (DP tuner) Econo tune on my 6.0 PSD. On cold starts I get a lot of blue/White smoke, for about 5 seconds and some sputtering,once its warm and I start it again later no smoke. I switched back to stock and also the SCT street tune one puff and nothing else for cold start nothing like the Econo tune. Any sugestions? Called Jody he is on Vacation.

Another thing I noticed with the Magnaflow was I can really hear the turbo which I expected but when I stand next to the exhaust tip there is a constant hissing sound is that normal? I only have about 50 miles on the exhaust.

 

The whine can be expected with a very open exhaust. For the smoke color, blue usually means oil and white means coolant. Keep an eye on your oil and coolant levels until you get in touch with DP.

Unless you didn't reconnect something under the hood, I can't imagine swapping the exhaust out would cause an oil or coolant leak or running rich. So I suspect it's in the tune and you might need a slight tweak.