Installer's Guide for Replacing Catalytic Converters

Catalytic converters are designed to function normally throughout an automobile's lifespan. If a converter fails, it is most likely a result of engine or emission sensor problems. These problems must be addressed and corrected before replacing the converter. If the converter is replaced before solving these other problems, the new converter will most likely fail soon after the installation. It cannot function properly if the other problems still exist.

If your vehicle's "Check Engine" light comes on, a repair technician should be able to correctly diagnose the problems caused by the engine or emission sensors. If the technician finds that damage has occurred to your catalytic converter, only then should you replace it.

Custom Fit

When to Replace a Catalytic Converter

Both EPA and CARB laws prohibit the removal or replacement of a properly functioning stock catalytic converter. EPA laws allow an aftermarket converter to be installed only in the following situations:

The vehicle has no converter.
A state or local inspection determines that the existing converter is damaged and the manufacturer would not be liable. Reasons for this replacement can vary widely, including but not limited to: lead poisoning, excess fuel in the exhaust system, a malfunctioning oxygen sensor, or road damage.
If an inspection reveals that the converter has been damaged, and it is under the OEM manufacturer's warranty, the manufacturer should replace it. Consult the vehicle manual or warranty booklet, or contact the vehicle manufacturer to determine the warranty. Typical warranties are from seven years and/or 70,000 miles to 15 years and/or 150,000 miles.

When you replace a converter, you must obtain proper documentation from a state or local emissions inspector stating that the damaged converter needs to be replaced. The installer must fill out a warranty card, then you must sign the card and send a copy to the manufacturer. Keep the original warranty card with your repair invoice.

EPA Requirements

When replacing a converter, be sure to comply with the following EPA requirements:

The converter must be installed in the same location as the original converter.
It must be the same type as the original converter (that is, two-way, three-way, etc).
It must be the correct converter model for the vehicle application, determined and specified by the manufacturer.
It must be properly connected to any air injection tubes on the vehicle. The location, position, or orientation of any oxygen sensors must not be altered as a result of the installation.
It must be installed with any other required converter for a particular application. Converters must not be consolidated, and no extra converters can be added.
The warranty card must be signed and returned to the manufacturer.

Find the Correct Replacement Catalytic Converter

Your vehicle's computer receives data from several sensors so that it can monitor and control your engine's performance. The performance of the catalytic converter is monitored by the computer too, so any replacement converter must perform like the original. If it doesn't, the computer could determine that it isn't functioning properly and produce an error code.

If your vehicle was originally intended for sale in California, its emissions control components are designed to work together to meet California's CARB standards. If the vehicle is registered in California, you must use CARB certified replacement parts, including a replacement catalytic converter. If your vehicle is now registered in another state (you may have moved, for example), the replacement converter should be California approved to ensure that the computer won't report an error.

Like California, the state of New York has adopted rules regarding the manufacture, sale, and installation of catalytic converters. New York, however, will allow you to replace the converter on a non-CARB certified (EPA or 49-state certified) vehicle with a non-CARB converter.

The Vehicle Emission Control Information label on your vehicle should tell you which standards your vehicle was designed to meet. You can find this label somewhere in the engine compartment of your vehicle, typically on the radiator support, strut tower, or on the hood.