If an emissions technician sees that you modded the engine (with added HHO) then he will not test it, he will fail it immediately. If it is tested then the NOX pollutant will be way too high.
Car manufacturers pay extra taxes for a fleet that has poor fuel economy. They would be the first to use HHO if it worked.
Car manufacturers pay extra taxes for a fleet that has poor fuel economy. They would be the first to use HHO if it worked.