WASHINGTON, D.C. — In a major move aimed at “freeing up” the American supply chain, President Trump and EPA Administrator Lee Zeldin announced today that the federal government is removing the requirement for Diesel Exhaust Fluid (DEF) sensors on all diesel equipment.
The announcement, made during the White House Great American Agriculture Celebration, is being hailed as a massive victory for farmers and truckers who have long complained that faulty sensors—rather than actual engine issues—have led to costly “deratements,” where vehicles are forced to a crawl or shut down entirely.
$13 Billion in Annual Savings
According to the Small Business Administration (SBA), removing the mandate will save the American economy an estimated $13.79 billion annually, with roughly $4.4 billion of that staying in the pockets of the agriculture industry.
“Failing DEF systems are a nationwide disaster,” said Administrator Zeldin. “Farmers and truckers should not be losing billions of dollars or days of work because of a faulty sensor. Today, we take another step in fixing this for all 50 states.”
How the New Guidance Works
The EPA’s new guidance allows manufacturers to bypass traditional Urea Quality Sensors—the components most prone to failure—and switch to Nitrous Oxide (NOx) sensors. This change aims to monitor actual pollutants rather than the fluid itself.
Key highlights of the policy include:
- Immediate Retrofits: Manufacturers can now issue software updates for existing engines to disable the old sensors without being penalized for “illegal tampering” under the Clean Air Act.
- Right to Repair: This builds on the February 2026 guidance that allows farmers to fix their own equipment in the field without being locked out by proprietary software.
- End of the “Limp Mode”: The administration is moving toward a total removal of “deratements” (speed limits) for new vehicles, ensuring that a sensor glitch won’t leave a trucker stranded on the highway at 5 mph.
Voices from the Cabinet
Agriculture Secretary Brooke L. Rollins noted that the partnership between the USDA and EPA has been “hand in glove” to rectify the problems facing rural America. Meanwhile, SBA Administrator Kelly Loeffler took aim at previous environmental policies, stating, “Few small businesses have been hit harder by the Green New Scam than those in the agriculture industry… we are taking another step to cut red tape.”
Environmental Standards Remain
The EPA clarified that today’s announcement does not weaken emissions standards. Instead, the agency argues that the standards will now be met through more reliable technology that works in real-world conditions.
The agency is still reviewing data from 14 major manufacturers to identify further opportunities to streamline diesel regulations and prevent future system failures.
