There are a couple ways to get S02 to H2S04. S02 + H20 >>> H2SO3- + 1/2 02 >>> H2SO4 OR S02 + 02 >>> 2 SO3 + H20 >>> H2SO4... Obvoiusly there are more but these two seem to be the most relevent. The second reaction is what I believe happens when SO2 comes out of a smoke stack, reacts with 02 and then with water to form acid rain... If SO2 is a by product of combustion (burning sulfer) can you get it to futher oxidize in your engine by burning it? I'm not sure.
I thought that was the purpose of a catalytic converter, to oxidize the NOx and SOx before they can be released to the atmosphere to form acids
However on the intake side of your engine, I guess you might be able to have enough H20 to react with the H2SO3??? It would also depend on the reaction rate of S02 + O2 which is probably much slower then 2 SO3 + H2O... But after combustion, I don't think there is enough O2 left to react with S02 in your exhaust system to cause a problem...
I'm not a chemist, but I would imagine that S02 doesnt cause a problem producing H2SO4, in N2O inducted engines, or else they would have chosen a different "denaturing" agent... But if anyone does try to inhale some N20 designed for cars... your lungs will be destroyed by Sulfuric acid, hence the reason its there...
Any Chemists out there that could help???
P.S. Even at whosale cost, it would seem that using Surgical grade N2O would make using it cost prohibitive to just burn in your car...