I think your right. In Texas you must pass a fairly stringent car inspection. If u don’t pass, you cannot register your vehicle which is certain to get you a ticket for “no inspection” and “no current registration” and you better have proof of insurance to show the cop too.
My son has a Passat diesel and we are currently wondering what to do.
So, it seems to me that to operate a legal car in Texas, as the law stands now, you will have to get it fixed.
Find some shop off the beaten path and take a chance that there is no check for the “fix” to the system that switches on the emissions controls when the car is checked?