President Donald Trump pardoned nine people convicted of violating the Clean Air Act by tampering with diesel vehicle emissions-control systems.On Friday, Trump announced six of the pardons on Truth Social, arguing that the men he granted clemency to were "persecuted by the Biden Administration" and punished for "fixing their car."Eight of the people Trump pardoned were diesel mechanics or car tuners who were prosecuted for selling and installing so-called "defeat devices" into trucks, according to a Fox News review of federal court records.These devices reprogram trucks to bypass federally required emissions controls and suppress diagnostic warnings.Without them, many diesel trucks can enter a "limp" mode that limits speed — sometimes to as little as 5 mph — until the emissions system is restored.President Donald Trump speaks during a rally at Mount Rushmore National Memorial on July 3, 2026, in Keystone, South Dakota.
(Chip Somodevilla/Getty Images)FORMER INDIANA REP STEPHEN BUYER RECEIVES FULL PARDON FROM TRUMP FOR 2023 INSIDER TRADING CONVICTIONTrucks can also enter this limp mode when emissions controls fail.These failures are extraordinarily common and have been causing massive headaches for truckers and farmers for years, according to the Environmental Protection Agency.People are more than willing to pay top dollar to mechanics who can do the job of disabling the emissions-limiting systems.Matthew Geouge, one of the pardon recipients, ran two companies that sold illegal tuning devices.
Just from the sale of those devices alone, his firms grossed more than $10 million, according to his December 2021 plea agreement.Emissions-capping technology, specifically Diesel Exhaust Fluid (DEF) systems, is also prone to malfunctions in extremely cold weather.A tractor trailer refuels with diesel fuel at a Kwik Star gas station in Mitchellville, Iowa, on Thursday, April 30, 2026.(Bryon Houlgrave/Bloomberg via Getty Images)TRUMP WILL WELCOME FARMERS AND RANCHERS TO ...