Sixteen. That’s how many civil Clean Air Act lawsuits the DOJ filed in the first year of Trump’s second term — a 76% drop compared to Biden’s first year, according to InsideClimate News. For independent shops and aftermarket parts buyers, the federal government just turned down enforcement heat to its lowest setting in two decades.
The rules haven’t changed. The appetite to enforce them has.
EPA Says Record Results. The Numbers Say Otherwise.
The agency’s public victory lap collides with watchdog data showing historic enforcement lows.
EPA press releases trumpet the “strongest enforcement and compliance results in years.” Meanwhile, the Environmental Integrity Project found 14 of 24 enforcement categories sitting at their weakest or second-weakest levels in recent history. A formal internal “compliance first” memo rescinded Biden-era guidance that pushed advanced monitoring and third-party audits. Fewer cases, louder press releases — like a restaurant posting five-star reviews while the health inspector finds roaches.
EPA simultaneously announced it advanced “Americans’ lawful right to repair their farm and other nonroad diesel equipment,” explicitly stating the Clean Air Act cannot justify manufacturers locking down repair tools or software. DOJ, separately, dismissed Biden-era criminal CAA prosecutions for emissions-diagnostic tampering, announcing on January 21, 2026 it would stop pursuing criminal charges for “check engine light”-type modifications. Automaker trade groups, however, contend that existing frameworks already provide sufficient repair access without requiring sweeping new mandates.
The policy signal is unmistakable — even if binding guidance for on-road vehicles doesn’t exist yet.
What’s actually shifting:
- EPA’s “compliance first” memo prioritizes working toward compliance before imposing fines
- DOJ dismissed criminal CAA tampering cases and halted new prosecutions for diagnostic-related modifications
- EPA right-to-repair guidance covers non-road diesel; on-road vehicles still lack formal criteria
- The REPAIR Act would mandate access to vehicle data, diagnostic tools, and telematics while banning manufacturer repair monopolies
- Clean Air Act anti-tampering provisions remain law — deleting emissions hardware is still illegal
Fixing Your Catalytic Converter Isn’t the Same as Deleting It
The emerging distinction between restoring compliance and gutting emissions hardware will define who actually benefits from this shift.
That line matters enormously. Aftermarket industry groups like MEMA frame the REPAIR Act as helping owners return vehicles to “compliant operational specifications” — not strip them bare. State programs in New York already let you choose any repair facility for emissions work, provided the hardware stays intact. The Union of Concerned Scientists warns the current landscape represents “a period of deep retrenchment against strong enforcement” — a counterpoint worth taking seriously when weighing how durable this softer posture really is.
The REPAIR Act would also grant owners rights over vehicle-generated data, including the ability to delete it. The catch: the current compromise bill largely codifies a 2014 automaker memorandum of understanding. Manufacturers keep sharing what they already agreed to share and retain control over deeper CAN-bus access — like a streaming service giving you a profile but not the recommendation algorithm. Environmental groups warn that relaxed enforcement could open loopholes for modifications that degrade air quality well beyond any good-faith repair. Dealers recommending a fuel filter replacement is one thing; the economics of independent repair are shifting in ways that touch far more expensive components.
If you’re restoring a broken emissions system with aftermarket parts at a neighborhood shop, federal pressure is lower than it’s been in a generation. Exploring DIY car fixes has rarely been more relevant given the current enforcement climate. Ripping out a particulate filter, though, remains illegal under the Clean Air Act regardless of how quiet the enforcers get. Policy moods shift. Statutes don’t.
