EPA vs CARB (What is the difference?)




Making the distinction between the two is hardly new. The line was drawn back in the late 60’s, but its significance has grown over the last few years. On January 1, 2009, California adopted and put into place, new laws regarding the manufacture, sale and installation of aftermarket catalytic converters. This year New York State has adopted those same laws.

This article is not about the laws themselves but rather one area of the law that seems to be the most confusing to those who may not fully understand the difference. That is the process of selecting the proper converter for an individual vehicle. Although the letter of the law in NY is not exactly as it is in CA, the principle is the same. If an OBD II vehicle is built to meet CARB standards, then it requires a California certified converter. For example, one significant difference is that NYS will allow EPA (Federal) certified vehicles to use a non-CARB part whereas California does not make that distinction.

The most important point to take away from this article is to recognize that a vehicle meeting the stricter CA standards from the factory has a catalytic converter, as well as other emission components on it, that is designed to meet those tougher standards. Therefore it is important to maintain the integrity of the system. In order to do that, you have to know what emission standard the vehicle is designed to meet and what components make up that system.

So how does a technician, retail counter person or vehicle owner retrieve this information? It can be found on the Vehicle Emission Control Information (VECI) label, located in the engine compartment. Typically it will be located on the strut tower, radiator support or on the underside of the hood. This label contains information about the emissions systems and components of that specific vehicle along with a statement referring to the standards to which that vehicle conforms. Refer to this information to help choose the proper catalytic converter for the vehicle.


The regulatory statement will indicate whether the vehicle conforms to EPA (Federal) or California (CARB) standards or both EPA and CARB (aka 50 State). As a side note, any label that has the phrase LEV (Low Emission Vehicle) in it conforms to CA standards. Some examples are LEV, ULEV, SULEV, NLEV or TLEV...to name a few. There are others, but I think you get the point. Any vehicle that meets CARB standards, automatically meets EPA. The reverse however is not true.


As I had stated earlier there were some differences between California regulations and the New York version of those rules. California for instance, does not distinguish between Federal and CARB standard vehicles. If the vehicle is registered in CA, it requires a CARB certified converter. These converters are labeled with an Executive Order (EO) number that verifies it has been approved for sale and/or installation in California. New York however, has indicated that they will allow non-CARB certified converters to be installed on vehicles that only meet the federal or EPA standard.


This information still applies. The absolute best service we can give our customers includes maintaining the integrity of the original equipment systems on their vehicles. Many times this does not necessarily mean using only OE parts but it does mean using parts that are manufactured to perform equally as well. When it comes to tail pipe emissions, each vehicle is required to meet a specific standard as defined by the Federal Test Procedure (FTP). The emission systems on that vehicle were designed to accomplish that task. Replacing the components of these systems with the proper parts is essential in maintaining the integrity of those systems and CARB regulations are designed to aid us in accomplishing the desired result. Using a replacement component not designed for the specific vehicle may cause unwanted problems such as illuminated MIL (Check Engine light), drivability problem or failed emissions test.