Well, I know one thing. Missouri used to use a company to do the emissions testing for them. Sometimes they would set up sensors on the entrance ramps for the interstate around here. I always made a point of "Rolling onto the throttle" when I went through their sensors... the test equipment would take readings, take your picture and you could get a letter in the mail asking you to please just send in your money, your vehicle has passed the emissions tests....
My wife caught me one day and said she was getting ready to mail the check off, I asked for what? She said, your truck! I was like,, um,, my truck doesn't require any emission testing,,,,
So I call the company, they said yes it does,, I said,, no it doesn't, It's a diesel,, they said, no it isn't!
Anyway,, apparently the above poster is right,, even a tuned 7.3 rolling coal, still passes!