Pre OBD2 Catalytic Converter Application Guide: Ensuring Compliance and Performance

Understanding the complexities of vehicle emissions systems is crucial, especially when dealing with older models. For vehicles manufactured before the introduction of the standardized On-Board Diagnostics II (OBD2) system, ensuring the correct application of parts, particularly catalytic converters, is vital for both environmental compliance and optimal vehicle performance. This guide provides a comprehensive list to verify the appropriate use of aftermarket catalytic converters on pre-OBD2 vehicles. By comparing the Executive Order (EO) number stamped on the catalytic converter against this list, you can confirm its correct application.

Understanding Pre-OBD2 Vehicle Emissions Systems

Pre-OBD2 vehicles, generally those made before the mid-1990s, utilize earlier emissions control technologies. Unlike modern cars with sophisticated OBD2 systems that continuously monitor and adjust emissions components, these older vehicles require careful attention to maintain their emissions systems effectively. The catalytic converter plays a pivotal role in reducing harmful pollutants from the exhaust. Using the correct catalytic converter is not only a legal requirement in many regions but also essential for the vehicle to run cleanly and efficiently. Incorrectly applied converters can lead to increased emissions, reduced engine performance, and potential failures in emissions testing.

Verifying Catalytic Converter Application for Pre-OBD2 Vehicles

To ensure you are using the correct aftermarket catalytic converter for a pre-OBD2 vehicle, you need to check the Executive Order (EO) number. This number is stamped directly on the catalytic converter and is issued by regulatory bodies like the California Air Resources Board (CARB) to certify aftermarket parts for emissions compliance. This list is organized to help you quickly verify if a catalytic converter, identified by its EO number, is approved for use on specific pre-OBD2 vehicle categories.

To use this guide effectively:

1. Locate the EO Number: Find the Executive Order (EO) number stamped on your catalytic converter.
2. Compare to the List: Match the EO number to the entries in the table below.
3. Verify Vehicle Category: Once you find a matching EO number, check the ‘Category’ column to confirm it corresponds to your vehicle type.

The vehicle categories are defined as follows to simplify identification:

• PC-1: Pre-OBD II passenger cars with a single catalytic converter per exhaust bank.
• PC-2: Pre-OBD II passenger cars with more than one catalytic converter per exhaust bank.
• T-1: Trucks with one catalytic converter per exhaust bank.
• T-2: Trucks with more than one catalytic converter per exhaust bank.

Pre-OBD2 Catalytic Converter Executive Order (EO) List

Important Inspection Alert

Due to a production labeling process issue, catalytic converters produced by International Muffler Company (d.b.a. Cherry Bomb/Maremont) may have labels with an extra zero added to their Executive Order (E.O.) number. When the CARB issued E.O. number ends in a single digit, the E.O. label might be marked as D-560-0X. 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. It’s important to note that this labeling issue does not impact the performance or legality of these catalytic converters during a Smog Check inspection. When verifying these E.O.s on CARB’s database, please omit the extra “0.” Use the regular E.O. number to access the correct Executive Order in the database.

Conclusion

Using this guide will help ensure that when replacing catalytic converters on pre-OBD2 vehicles, you select and verify the correct, compliant aftermarket part. Proper catalytic converter application is crucial for maintaining vehicle emissions standards, ensuring optimal engine performance, and passing required inspections. Always double-check the EO number and vehicle category against this list and consult with a qualified mechanic if you have any doubts. By taking these steps, you contribute to cleaner air and keep your pre-OBD2 vehicle running its best.