Yes. In California, operating a vehicle on public roads without a catalytic converter or with an emissions-control system that has been removed or tampered with is illegal. The state requires emission-control equipment to be intact and functioning, and violations can lead to tickets, fines, and mandatory repairs.
What the law says
California law, including the Vehicle Code and CARB regulations, requires that catalytic converters remain installed and functioning on on-road vehicles. It is illegal to operate on a highway a vehicle whose emission-control system has been removed, bypassed, or damaged.
Here are actions that are typically illegal under state law:
- Removing a catalytic converter or bypassing the emissions-control system
- Driving a vehicle that lacks a catalytic converter on public roads
- Tampering with sensors or other emission-control devices to bypass the converter
In short, altering or removing emission-control equipment to disable the catalytic converter is illegal for on-road use in California.
Penalties and enforcement
Violations are generally treated as infractions and can result in fines, citations, and requirements to repair the emissions equipment before the vehicle can be legally operated on public roads. California also offers a fix-it ticket program in some cases, which allows the driver to correct the problem and have part of the fine dismissed after proof of repair.
Enforcement focuses on ensuring vehicles meet California emission standards and pass required inspections and smog checks. The exact penalties can vary by county and the specifics of the violation.
- Infraction or citation for removal or tampering with emissions equipment
- Requirements to reinstall a catalytic converter and bring the vehicle into compliance
- Impact on vehicle registration and smog-testing status
- Possibility of a fix-it ticket and dismissal of part of the fine upon proof of repair
Penalties can escalate in cases involving repeated violations or significant environmental risk, underscoring the state’s emphasis on reducing vehicle emissions.
What to do if your car is missing a catalytic converter
If your vehicle currently lacks a catalytic converter, do not operate it on public roads. Arrange repair with a licensed shop to reinstall a CARB-compliant catalytic converter and ensure the rest of the emissions system is intact. You will likely need to pass a smog check to renew registration.
Steps to bring the vehicle into compliance:
- Replace the catalytic converter with a CARB-compliant or factory-equivalent part
- Have the repair performed by a licensed mechanic and verify that the entire emissions system is functioning
- Keep all receipts and documentation of parts and labor
- Schedule and pass a California smog test to confirm compliance with emissions standards
After completing the repair and passing inspection, the vehicle can be legally operated on California roads again. Consult the DMV for any specific steps required to renew registration after a repair.
Summary
California enforces strict rules requiring catalytic converters to remain installed and functioning on vehicles driven on public roads. Driving without a converter or with tampered emissions equipment is illegal and can lead to tickets, fines, and mandatory repairs. The fix-it ticket option and smog checks provide paths to restore compliance and resume normal operation.