HOW TO SELECT THE RIGHT CATALYTIC CONVERTER

When selecting the right replacement catalytic converter for your vehicle, several key factors must be considered. In this guide, we break down catalytic converter emissions regulations by state, explain how to identify your vehicle’s emissions system, and quickly outline the differences between direct-fit and universal catalytic converters to help you choose the correct option.

The most important factor is the state in which the vehicle is registered and operated, as emissions legality is determined by registration location and not where the vehicle was purchased or driven.

UNDERSTANDING EMISSION STANDARDS: FEDERAL EPA VS. CARB

There are two primary catalytic converter emissions standards in the United States:

• Federal/EPA compliant

• California/CARB compliant

Some states follow Federal EPA regulations, while others have adopted California Air Resources Board (CARB) standards. These standards may be different from the state in which the vehicle is registered and applicable to specific model years of vehicles based on the make and model of the application. Always base your converter selection on where the vehicle is registered, not where it was purchased or previously operated.

How to Identify Your Vehicle’s Emissions System (OBDII Vehicles)

For vehicles manufactured in 1996 or newer:

1. Locate the Vehicle Emissions Control Information (VECI) label

   • Typically found under the hood, on or near the underside of the hood, the suspension tower or the radiator shroud.

2. Identify the emissions certification

   • Listed as “Federal” or “California”

3. Save or photograph the label for reference

If the VECI label is missing, contact your dealer with your VIN to obtain emissions information.

Pre-OBDII vehicles (1995 and older) do not require this step.

EPA/FEDERAL AND NON-CARB COMPLIANT STATES:

Most states adhere to Federal EPA emissions regulations. 

MagnaFlow offers three grades of catalytic converters to meet the needs of customers in Federal emissions regulated states: OEM grade, HM grade and Standard grade.

• OEM Grade
  Designed for OBDII (1996 or newer) vehicles with California and Federal emissions systems registered outside CARB-regulated states. Features higher precious metal loading for OE-like performance.

• HM (High-Metal) Grade
  Compliant with OBDII vehicles using Federal EPA emissions systems. May be used on some California-emissions vehicles when registered outside CARB states.

• Standard Grade
  Designed for pre-OBDII vehicles (1995 and older).

Important: EPA-only catalytic converters cannot be sold or installed in California, Colorado, or New York.

CARB REGULATED STATES:

California, Colorado, and New York adhere to emission standards set through the California Air Resources Board (CARB).

The state of California has the strictest emissions standards in the United States. This, combined with the fact that the state also has the largest automotive market in the country means that California is uniquely positioned to influence the emissions regulations of other states, such as Colorado and New York. In fact, Colorado and New York adopted the same standards as those set by the California Air Resources Board (CARB). As a result, these CARB regulated states require vehicles registered in their jurisdiction to be fitted with CARB compliant catalytic converters. 

Vehicles registered in these states must use CARB-compliant catalytic converters with a valid Executive Order (EO) number. To ensure that you select the right converter, it’s important to follow the steps below.

CARB Compliance Requirements

• CARB-approved catalytic converter

• Matching Engine Family Number (EFN) or Test Group Number

• EO number stamped or etched on the converter body

To find your EFN:

1. Locate the VECI label under the hood

2. Identify the Engine Family Number (EFN) or Test Group Number

3. Save or photograph the information for future reference

If importing a non-compliant/FED vehicle into California, a state referee inspection may be required.

Note: If your vehicle is OBDII (1996 or newer), MagnaFlow's Shop by Vehicle tool allows you to select the relevant EFN number for your vehicle. Once you input all information on your vehicle, you will then be shown all compatible direct-fit and universal converter options. Pre-OBDII vehicles can skip the VECI/EFN step and use basic vehicle information to find the right California Pre-OBDII catalytic converter.

MAINE:

Maine follows a hybrid emissions policy (CARB or FED) that depends on vehicle year and emissions systems.

In Maine your vehicle will need either a California/CARB or Federal/EPA compliant catalytic converter. Qualifiers are listed below:

• 2001 and newer California-emissions vehicles: CARB-compliant converter required (FED/EPA converter not allowed)

• 2000 and older California-emissions vehicles: Federal EPA converter allowed

• Federal-emissions (non-California) vehicles: Federal EPA converter allowed

Note: Using MagnaFlow's Shop by Vehicle tool, you can select the state that your vehicle is registered in. Assuming you've selected your vehicle's state as Maine, the following option is important to consider. If your vehicle is a 2001 or newer with a California emissions system, you will next be asked to pick the correct EFN from those listed. Once you’ve completed those steps, the page will display all the MagnaFlow replacement catalytic converters that we have to offer for your vehicle for the state it’s registered in. Occasionally, additional information is required.

Quick Reference: Catalytic Converter Requirements by State

Converter Selection by Vehicle Type

As the name implies, direct-fit catalytic converters are designed to replace the specific application's OEM (original equipment manufacturer) part directly without modification—no fabrication required. Such precision is possible thanks to extensive use of 3D laser scans and modeling to ensure perfect, OEM-like fitment. Alternatively, universal catalytic converters offer compatibility to a wide range of vehicles based upon its compatible design and specific emissions standard loading. As a result of this adaptability, universal catalytic converters generally require additional fabrication, for which professional installation is highly recommended.

NEED HELP?

No matter which MagnaFlow catalytic converter you purchase, you’ll be getting the same corrosion resistant stainless-steel construction, engineered to keep the check engine light off. If you have further questions regarding picking the right converter or need help with installation, please feel free to contact us at (800) 990-0905 and we’ll be happy to help. Check out our social media accounts (Facebook, Instagram, YouTube and Twitter) and our MagnaFlow Blogs to stay up to date on upcoming product releases.