Pre-OBD2 Catalytic Converter Application Guide for Mechanics

Ensuring the correct catalytic converter is fitted to pre-OBD2 vehicles is crucial for emissions compliance and vehicle performance. This guide helps automotive professionals verify the appropriate application of aftermarket catalytic converters by referencing Executive Order (EO) numbers. Use this information to confirm that the catalytic converter installed is approved for the specific vehicle category.

Understanding Pre-OBD2 Catalytic Converters

Before the standardization of On-Board Diagnostics II (OBD2) in 1996, vehicles employed various diagnostic systems, often referred to as pre-OBD2 or OBD-I. These earlier systems had less comprehensive emissions monitoring capabilities compared to OBD2. Catalytic converters in pre-OBD2 vehicles are essential components in reducing harmful emissions, converting pollutants like hydrocarbons, carbon monoxide, and nitrogen oxides into less harmful substances. Due to the variety of pre-OBD2 vehicle makes and models, ensuring the correct aftermarket catalytic converter is installed is vital for maintaining emission control effectiveness and legality.

Verifying Catalytic Converter Application with Executive Orders

The California Air Resources Board (CARB) issues Executive Orders to certify aftermarket catalytic converters for use on specific vehicles. These EOs are critical for verifying that a replacement catalytic converter is legal and meets emission standards. Each catalytic converter will have an EO number stamped on it. To verify if a catalytic converter is appropriate for a pre-OBD2 vehicle, compare this EO number against the following list.

If the EO number on the catalytic converter matches the vehicle category information in the table below, then the application is verified as correct. The vehicle categories are defined as follows:

• PC-1 – Pre-OBD II passenger cars with a single catalytic converter per exhaust bank. This is typical for inline engines or single exhaust systems.
• PC-2 – Pre-OBD II passenger cars with more than one catalytic converter per exhaust bank. Often found in V-engines with dual exhaust systems, where each bank might have its own converter or multiple converters.
• T-1 – Trucks classified as light-duty trucks with one catalytic converter per exhaust bank. Similar to PC-1, but for trucks.
• T-2 – Trucks classified as light-duty trucks with more than one catalytic converter per exhaust bank. Similar to PC-2, but for trucks.

Inspection Alert for Maremont Catalytic Converters

Please note a specific inspection alert regarding catalytic converters manufactured by International Muffler Company, also known as Cherry Bomb/Maremont. Due to a labeling issue during production, some catalytic converters may have an extra zero in their Executive Order (E.O.) number on the label. Specifically, if a CARB issued E.O. number ends in a single digit, the label might incorrectly show an extra ‘0’, such as D-560-0X instead of D-560-X.

Affected Executive Orders include D-560-3, D-560-5, D-560-6, D-560-7, and D-560-8, which may appear on the converter as D-560-03, D-560-05, D-560-06, D-560-07, and D-560-08, respectively. International Muffler Company is aware of this labeling issue and is working to correct their labeling process.

It is important to understand that this labeling irregularity does not impact the performance or compliance of these catalytic converters. During a Smog Check inspection, if you encounter an EO number with this extra zero, please verify it against CARB’s database by entering the correct E.O. number without the extra “0”. This will allow you to access the accurate Executive Order information and confirm compliance.

Conclusion

Properly identifying and applying pre-OBD2 catalytic converters is essential for maintaining vehicle emissions standards and ensuring regulatory compliance. By utilizing this guide and verifying the Executive Order numbers, automotive technicians can confidently install the correct aftermarket catalytic converters on pre-OBD2 vehicles. This not only ensures optimal vehicle performance but also contributes to cleaner air quality. Always refer to the most up-to-date CARB resources and guidelines for the latest information on catalytic converter regulations and approved applications.