“The action today will allow engine manufacturers to update their systems to monitor the pollutants we are targeting rather than the diesel exhaust fluid itself, which has caused many of the system failures,” said U.S. Secretary of Agriculture Brooke Rollins. “This powerful step will provide much needed relief, but we will continue to work towards a solution that protects the environment while eliminating damages to farmers and truckers nationwide.”

“Few small businesses have been hit harder by the Green New Scam than those who make up America’s great agriculture industry, where massive regulatory burdens have crushed family farms and driven up grocery costs,” said SBA Administrator Kelly Loeffler. “Today, by eliminating DEF mandates, the Trump administration is taking yet another step to free up hardworking Americans to focus on the vital work of feeding, clothing, building and fueling our nation.”

The preliminary review of the warranty data suggests DEF sensor failures are a significant source of warranty claims and DEF-related inducement. Farmers and truck drivers should not have their vehicles stop working because a sensor isn’t working properly. EPA is taking immediate action on this new information. The agency’s new guidance makes clear that under existing regulations, manufacturers can stop inaccurate DEF system failures by removing traditional emission sensors, known as urea quality sensors, and switching to nitrous oxide (NO_x) sensors.

EPA also affirms that approved NO_x sensor-based software updates can be installed on existing engines without being treated as illegal tampering under the Clean Air Act. This is in line with EPA’s February 2026 Right to Repair clarification guidance, which removed a major barrier keeping farmers from fixing their faulty DEF systems in the field. EPA anticipates the switch will greatly curb errors that traditional sensor technologies have been prone to and reduce the issues Americans face with inaccurate DEF failures.

In August 2025, EPA issued new, clear guidance calling on engine and equipment manufacturers to revise DEF system software in existing vehicles and equipment to massively reverse deratements that harm farmers and truckers. In response to this guidance, manufacturers have started making this new and improved software available to Americans in some existing vehicles and will be extending the improvements to owners of older equipment.

In the near future, EPA will be issuing a new deregulatory proposal that will completely remove all DEF deratements for new vehicles and engines. With these changes, sudden speed losses, which compromise safety and productivity, will be an issue of the past.

EPA will continue reviewing data collected from manufacturers and use this information to identify opportunities to improve emission systems. Given the breadth of EPA’s data request, some of the largest manufacturers required additional time to compile and submit their data. EPA will give the public a complete assessment of the data collected once all data is received.

This announcement does not weaken or remove emissions standards, according to the agency. Instead, it ensures that those standards are met in a way that actually works in the real world. EPA remains committed to protecting human health and the environment while ensuring that the Americans who feed, clothe and power our economy are not burdened by unnecessary system failures.

For more information, please see EPA’s Diesel Exhaust Fluid.

Editor’s note: This article adapted from a news release provided by the EPA. [Lead photo by THEPALMER from Getty Images.]

Angus Beef Bulletin EXTRA, Vol. 18, No. 4-A