Don't get me wrong, it's not like you hear of this happening everyday. In fact in Northern Ontario it's not even required to have the emisssions test done when a vehicle is sold. BUT!!! it is fully legal for uncle MOE to pull a vehicle over and write a test requirement if they believe that any emissions control has been altered or removed. Alot of the ricers around in southern Ontario have been pulled for the fart cans. Then when the MOE officer checks under the vehicle if any part looks altered or is missing they get written up. Also if your diesel is just parked at the side of the road they can just test the fuel in the tank, without your permission. And if they find coloured fuel yer up the creek. I forget how much the fine is but it's easily more than what you would have saved by buying off-road fuel.