So far I have not said one thing about how exactly or what exactly has to be done to make the stock control systems see false or tweaked signals which I believe is where the line is drawn here. I have mentioned nothing about the electronics nore the physical modifications aspects.Nothing like walking the line. TC be careful, I didn't mean to bring it.
It's still interesting stuff. But, not legal, e.g. Cool but, not cool.
Legality wise I find it's just politics based on greed and misinformations disguised as good environmental blah blah blah.
The real gainful changes to vehicles emissions came from the reformulation of fuels over the last 40+ years. Granted they watered it down and made it so it goes rotten in a few months now but it did change the way it burned in the engines and to what effects of combustion byproducts are created from it.