DOJ Drops Criminal Prosecutions in Diesel Delete Cases

DOJ Shifts Policy on Criminal Charges for Diesel Delete Cases

The U.S. Department of Justice (DOJ) announced a major change in how it will handle certain Clean Air Act cases tied to diesel truck modifications. In a post from its Environment and Natural Resources Division on X, the DOJ said it will no longer pursue criminal charges based on claims of tampering with onboard diagnostic devices in motor vehicles. 

They said it is using its enforcement discretion to step away from criminal prosecution in these cases. However, enforcement is not ending. Instead, the DOJ said it will still pursue civil enforcement when appropriate, working with the Environmental Protection Agency (EPA). The shift follows years of debate over diesel deletes and emissions rules and signals a move away from criminal penalties toward civil actions.

DOJ Policy and What Diesel Deletes Mean

Diesel deletes usually refer to the removal or disabling of emissions control systems on diesel engines. These systems include parts like diesel particulate filters, exhaust gas recirculation valves, and selective catalytic reduction systems.

Tunes are software changes made to a truck’s engine control module. Some tunes are legal. They aim to improve performance or fuel economy while keeping emissions systems intact. Other tunes are not legal. They are designed to bypass emissions controls or shut off warning lights after parts have been removed.

Federal law has long banned tampering with emissions equipment. The Clean Air Act makes it illegal to remove or disable pollution control devices. It also bans the sale of parts meant to defeat emissions systems. For years, both the EPA and DOJ enforced these rules through civil penalties and criminal prosecutions.

How This Affects Truck Drivers and Shops

This policy change could have real impacts across the trucking industry. For truck drivers, the shift means that future cases tied to onboard diagnostic tampering are less likely to lead to criminal charges. However, civil penalties can still be costly. 

For repair shops and tuning companies, the change may reduce the risk of criminal prosecution. But it does not make diesel deletes or illegal tunes legal. Selling or installing defeat devices remains a violation of federal law.

The EPA still has the authority to issue fines and take civil action. In recent years, the agency has targeted both small shops and large companies involved in the diesel delete market. So while the threat of criminal court may be lower, the risk of enforcement has not gone away.

Change Follows High-Profile Cases

The DOJ policy shift follows years of public debate around diesel delete enforcement. Several high-profile cases brought national attention to the issue. One of the most widely discussed cases involved Troy Lake, a truck driver who faced criminal charges tied to alleged Clean Air Act violations. Lake’s case drew support from lawmakers and industry groups. They argued that the penalties were too harsh. He later received a presidential pardon. That decision brought renewed attention to how emissions cases are handled.

Around the same time, lawmakers introduced the Diesel Truck Liberation Act. The bill aimed to limit the EPA’s authority over emissions modifications on certain trucks. While the bill did not become law, it reflected growing concern about how federal agencies regulate diesel vehicles.

Lawmakers also sent letters calling for clemency in emissions cases. They urged agencies to rethink criminal enforcement strategies. These efforts added pressure on regulators to review their approach. The DOJ’s latest move appears to respond, at least in part, to that broader conversation.

DOJ Says It Will Focus on Fair Enforcement

Even with the DOJ stepping back from criminal charges in these cases, risks remain. Civil fines can still be costly. Some past cases involved penalties in the tens or hundreds of thousands of dollars. The EPA can still order repairs or require compliance steps. These actions can take trucks off the road and reduce income. Shops and tuning companies also remain at risk. Selling or installing defeat devices is still illegal. Civil enforcement can still shut down businesses and lead to large settlements.

 In its announcement, the DOJ said the new policy supports fair enforcement. The department said it wants to focus its criminal tools on the most serious cases. It also said it wants to use government resources wisely. By shifting diesel delete cases to civil court, the DOJ is trying to strike a balance. It aims to enforce environmental law without relying on criminal penalties in every case. At the same time, the DOJ said it remains committed to protecting air quality. It also said it will continue working closely with the EPA.

What Comes Next for DOJ Diesel Delete Enforcement

The DOJ policy change marks a clear shift in how diesel delete cases may be handled at the federal level. However, some questions remain. As of now, the DOJ has not posted a formal press release on its official website. The announcement only appears in a social media post from its Environment and Natural Resources Division. It is also unclear how the policy will apply to ongoing cases or past investigations.

For truck drivers and repair shops, this move may reduce the risk of criminal court. Still, it does not remove legal or financial risks. Diesel deletes remain illegal, and civil penalties can still be severe. As the DOJ approach takes effect, its real-world impact will become clearer.