A controversial proposal to eliminate federal enforcement of diesel emissions controls is gaining new momentum in Congress, with a House version of the Diesel Truck Liberation Act now introduced alongside an existing Senate bill.
Representative Mike Collins (R-GA) introduced the House companion to the Diesel Truck Liberation Act, mirroring legislation first introduced in the Senate in October 2025 by Senator Cynthia Lummis (R-WY). The Senate version, S.3007, was read twice and referred to the Committee on Environment and Public Works, where it remains pending.
The legislation would fundamentally reshape the federal government’s role in regulating vehicle emissions, particularly for diesel trucks, by prohibiting enforcement of key provisions under the Clean Air Act.
According to the Senate bill text, the Diesel Truck Liberation Act would prohibit any federal law from requiring manufacturers, importers, or distributors to install, certify, or maintain emissions control devices or onboard diagnostic systems on vehicles and engines.
The bill also removes the Environmental Protection Agency’s authority to enforce emissions-related requirements under the Clean Air Act and eliminates civil or criminal liability tied to the manufacture, sale, or use of vehicles without those systems. In addition, it would invalidate existing federal regulations governing emissions control devices and mandate that any related criminal penalties be vacated and records expunged.
The introduction of a House companion bill expands the legislative pathway for the proposal, signaling growing support among some lawmakers for limiting EPA authority over vehicle emissions enforcement. While the Senate bill has not advanced beyond committee since its introduction, the addition of a House version increases the visibility of the issue and sets the stage for potential parallel consideration in both chambers.
The legislation specifically targets enforcement actions tied to emissions system tampering, which are currently prohibited under federal law.
For commercial fleets, the bill raises significant questions about compliance, cost, and operational strategy. If enacted, the legislation would remove federal requirements for emissions control systems on diesel trucks, potentially reducing maintenance costs tied to aftertreatment systems such as diesel particulate filters and selective catalytic reduction.
At the same time, the proposal would introduce uncertainty around how state-level regulations would interact with a rollback of federal enforcement, particularly in states with stricter emissions standards.
For now, both the Senate and House versions of the Diesel Truck Liberation Act remain at the introduction stage, with no further legislative action taken.
