The EPA also doesn't like the idea of people making things not pass emissions.
This https://www.wep-inc.com/inspection-maintenance-programs/texa... is hilarious. You arent testing car emissions, you are reading car computer self report.
In EU, NZ/AU and probably many more places Tailpipe gas emissions test is routine. There are even mobile units with portable Emissions measurement systems. Meanwhile even California doesnt mandate tailpipe tests :o
When I press people on what parts of their tractors they can't do now it generally comes down to something that would make the tractor not pass emissions if it was tested. Parts and computer test equipment is readily available.
US on the other hand legislated computer DRM "for engines" because its cheaper/faster, anything beyond is a super special case. My favorite is actual tailpipe test commercial trucks must pass in NY - they test opacity of gas aka "is the smoke visible?" :o and look for physical presence of all mandated emission hardware for that model/year/exemption status. All of that theater instead of using proper exhaust gas analyzers.
>Parts and computer test equipment is readily available.
Can you download standalone John Deere service software? or did you mean signing up for their paid SAAS package?