Is it legal to delete DEF system?
Is it legal to delete DEF system? Given the open availability of this service, a farmer could be forgiven for believing that DEF modifications are legal. They're not. In the U.S., the EPA Clean Air Act prohibits anyone from tampering with an emission control device on a motor vehicle by removing it or making it inoperable. Is a DEF delete worth it? The catch about a DEF system is that you have to keep its fluid reservoir filled regularly to keep it functioning properly. This doesn't just take time – it costs money, too. Deleting your DEF system can help...