Removing a catalytic converter without replacing it is illegal under the federal law (42 USC 7522, pdf 41 KB). Vehicles without properly functioning emission controls emit high levels of pollution.
The resale of a vehicle which has already had the catalytic converter removed is not specifically addressed by federal law. Therefore, the person who removed the converter violated federal law, but not necessarily the person who sold the vehicle. State or local laws, however, may cover the sale of vehicles that have had the emission control system removed, disabled, or tampered with.
- Office of Transportation and Air Quality Frequent Questions
- The Plain English Guide to the Clean Air Act
If you have further questions they can be directed to the following EPA employees in the Office of Transportation and Air Quality: