Sometimes, the spotlight can have drawbacks.

A federal judge has ordered the stars of the Discovery Channel show Diesel Brothers to pay an $851,451 fine for air pollution, according to The Salt Lake Tribune.

David "Heavy D" Sparks and David "Diesel Dave" Kiley, along with other defendants in the case, run a Utah-based shop that modifies diesel trucks.

These modifications often include tampering with emissions-control equipment, hence the fine.

U.S. District Court Judge Robert Shelby found in 2019 that the defendants had violated the Clean Air Act and Utah state law by removing emissions-control devices from the trucks they modified. Now the defendants must pay $761,451 to the federal government and $90,000 to Davis County Utah.

Shelby also issued an order stating that the plaintiffs, Utah Physicians for a Healthy Environment (UPHE) could submit their attorney fees for the defendants to pay.

Modified Ford F-650 featured on

Modified Ford F-650 featured on

The plaintiff's attorneys previously told the judge they had fees of $1.2 million, Cole Cannon, a lawyer for the defendants, told the Salt Lake Tribune, adding that his clients had made a settlement offer that would have seen a greater share of the penalties go to Utah rather than the federal government.

UPHE filed its lawsuit in 2016. It subsequently bought one of the modified trucks and had the vehicle emissions tested, according to the Salt Lake Tribune. The results reportedly showed 36 times more pollution and 21 times the amount of particulate matter of a stock truck.

Shelby cited those results in his ruling, along with videos of trucks billowing plumes of black smoke.

Known as "rolling coal," it's a popular way for owners of modified diesel trucks to show off. While owners also modify trucks for other reasons, such as increasing power, it often involves tampering with emissions controls.

Kits for a variety of vehicles have been available for years, without receiving much attention from regulators. The high profile created by a television show likely made the "Diesel Brothers" more prominent targets for litigation.

But regulators are cracking down on truck manufacturers that try to skirt emissions rules. In 2018, a recall of diesel engines by Cummins, which supplies engines for Ram Heavy Duty trucks, became the biggest diesel recall in Environmental Protection Agency—surpassing even that of Volkswagen vehicles.