It is illegal and prohibited in the state of California to select or install a catalytic converter based on the vehicle weight, physical shapes, engine size, configuration or the pipe diameter. Effective January 2009 and according to the California Vehicle Law Code, the manufacturers, resellers and installers of the aftermarket catalytic converters have to follow certain instructions while they sell, manufacture or resell the aftermarket catalytic converters. The following are the instructions on what type of converters are currently legal in California.
- If it is a new OE or an Original Equipment converter, it is a California legal catalytic converter which means it is currently legal to use this converter in the state.
- The new aftermarket converters are legal for use in the state only if the converter model is exempted by ARB.
- The certified used OE converters are legal for use only if the converter is tested and approved for a resale by the ARB authorized business.
- The used aftermarket converters or the uncertified used OE converters are not legal for use in the state of California.
A list of approved aftermarket converters are mentioned on the ARB website. Any kind of ARB exemptions are only issued through the Executive Orders. These orders can be sorted by an Executive Order number or by the Converter manufacturer only for the pre-OBD II or OBD II converters. The aftermarket converters that are sold after January 2009 would have the ARB Executive Order Number on the converter shell.
One should always consult a converter manufacturer’s catalog so as to verify the catalytic converter model. This has to fit the specific vehicle application and should be approved to be used in the state of California. The certified used OE converters are tested for their current level of performance and how it can perform in future. The test again is conducted by the ARB authorized business. Cosmetic refurbishing, replacement of flanges or end pipes, polishing the converter’s shell and the like are legal.
The California legal catalytic converters in Non-OBD II vehicles – installation of these converters are approved only if they fall under the below categories:
- Passenger cars that have dual or single exhaust systems with just one catalytic converter.
- Medium duty or light duty trucks with dual or single exhaust systems with just one catalytic converter.
- Passenger cars with dual or single exhaust systems with one, two or more than two catalytic converters.
- Medium duty trucks or light duty trucks with single or two exhaust systems with one, two or more than two catalytic converters.
A single configuration is for vehicles that come with a configuration of a single OEM catalytic converter per exhaust bank. The dual configuration is for vehicles that come with a configuration of OEM converters with two or more than two converters per exhaust bank. The California legal catalytic converter should have clear labels with ARB EO Number, Part Number, Date Code, Directional Flow Arrow, half inch tall numbers and the label should be visible from a five feet distance.