Up until now, shops were able to get away with removing the devices under the guise of them being for “race use only.”

However, the EPA certainly isn’t stupid. They are very aware that these “race use only” vehicles have been finding their way to the streets. Because of that, they have now deemed any tampering with the emissions devices will be completely illegal.

It’s hard to pin down exactly how many diesel shops have been hit. However, from what we understand, the EPA has been making its rounds. These rounds will restrain the shops from selling tuning devices that tamper with the systems. Just as an example, as a part of a recent settlement, one diesel shop was permitted from selling current tuning devices and will need to prove that their future tuning devices won’t violate the emissions standards.

I think it's stupid to enforce emissions limits in areas that are in-compliance with emission standards.