The Environmental Protection Agency (EPA) recently announced the removal of the Diesel Exhaust Fluid (DEF) sensor requirement for all diesel equipment, stating that the sudden speed losses and shutdowns caused by DEF system failures unacceptably compromise safety and productivity. The agency vowed to continue to pursue all legal avenues to address American’s complaints and keep farmers from losing days in the field.
The new guidance, which removes DEF sensors, is anticipated to save farmers $4.4 billion a year in repairs and lost productivity. The move is also estimated to provide $13.79 billion a year in savings to Americans, according to the U.S. Small Business Administration.
“Failing DEF systems are not an East Coast or West Coast or Heartland issue; it is a nationwide disaster,” said EPA Administrator Lee Zeldin in a news release. “I have heard from truck drivers, farmers, and many others complaining about DEF and pleading for a fix in all 50 states I visited during my first year as EPA administrator. Americans are justified in being fed up with failing DEF system issues.
“Today, we take another step in furthering our work by removing DEF sensors,” he continued. “Farmers and truckers should not be losing billions of dollars because of repair costs or days lost on the job.”
EPA Reacts Quickly
On February 3, the EPA requested critical data on DEF system failures from manufacturers that account for over 80% of all products used in DEF systems. The EPA plans to use this data to address the DEF failure issue. The agency has already received data from 11 of the 14 manufacturers.
Preliminary review of the warranty data suggests that DEF sensor failures are a significant source of warranty claims and DEF-related inducement. This guidance is a direct response to the data, making it clear that under existing regulations, manufacturers can stop inaccurate DEF system failures by removing traditional emission sensors, known as urea quality sensors, and switch to nitrous oxide sensors.
EPA also affirms that the approved nitrous oxide sensor-based software updates can be installed on existing engines without being treated as illegal tampering under the Clean Air Act. The EPA anticipates the switch will greatly curb errors that traditional sensor technologies have been prone to and reduce the occurrence of inaccurate DEF failures.
Industry Responds
John Deere and AGCO were both present for the announcement.
“John Deere applauds the EPA's leadership to provide as much flexibility through agency guidance as possible to limit the frequency of false DEF-quality inducements,” said Kyle Gilley, vice president for global government affairs at John Deere. “Today’s announcement builds upon EPA guidance from February 2026, requested by John Deere, to provide farmers additional tools to complete emissions-related repairs. These announcements are a win for farmers and their ability to keep modern equipment operating in the field.”
EDITOR’S TAKE:
EPA was a bit overzealous in pursuit of clean air standards that produced cleaner emissions than the air entering the engine initially. And the move was expensive for farmers and truckers. And let’s not overlook the fact that the introduction of DEF sensors has increased breakdowns and repair costs. Sure, we all want clean air, no debate here, but at what cost? This move by EPA will help reach a more moderate and sustainable solution.
Speaking of sustainability, be sure you let your ag customer know about CAD Protect. It is a program designed specifically to cover truck warranty issues when used on a farm or ranch. Often, the OEM warranty is void if used in those settings. It’s a great program and can help your F&I bottom line!
