It's not John Deere that was doing that, just some Korean companies exploring the opportunity and importing to the US. John Deere is located in the US and too afraid of the whimsical interpretations of regulators to try something like that, I think.
There was no "screw" for the commercial John Deere tractors with emissions controls, that I know of, as that was locked down to prevent "repair."
There was no "screw" for the commercial John Deere tractors with emissions controls, that I know of, as that was locked down to prevent "repair."