to pass inspection in most states the vehicle has to be plugged into the state approved OBDII reader it checks against an epa database the version of the cars ecu software given that all versions of the ecu software that the epa deems as fraud will be invalidated any vehicle that shows up to get inspected that when plugged in returns that version will fail and not be allowed to be registered that year. the epa takes this stuff very seriously texas checks not only your ecu version but also does a tail pipe test, and then checks the insurance database to make sure your insurance is valid before they give you a valid reg sticker. so flashing back to the old version will fail a vehicles obd2 test. i guess one could flash the new get inspected then flash the old back once a year but most people do not have the tech programer a sinple obd2 reader wont do it only dealership level programmers will and the dealer could just as easy encypt the ecu a lot already are encrypted.
Remember the good old days when this was a Free Country?
Emissions testing varies from State to State. I’m not sure how many States even Test Diesel Cars. I think many States don’t require Emissions Testing at all (what a dream).
Wish I lived in one of those.
Take the Drivetrain out and put it in an Older Car that is exempt from Smog Testing. Some States have a rolling Year exception and some States like CA have a fixed Year, which I think is 1976. Human Ingenuity knows no bounds. LOL
Where there’s a will there’s a way, or a Corpse.