What should you do if you are doing a smog inspection and you notice there is an extra Aftermarket-Catalytic-Converter install?

Should this vehicle pass the test or should you fail, this page should answer that question. 

Bio Diesel Conversion Kits

For the purposes of a Smog Check inspection, biodiesel kits installed on 1998-2003 model year vehicles are acceptable without an ARB EO exemption. ARB EO exemption is required for 2004 and newer vehicles


Catalytic Converters

Smog Check Inspectors must check that all required catalytic converters (CATs) are present and appear to be properly installed and install in the correct place.

This includes making sure there are the correct number of CATs, that they are installed in the original location(s), and that they have no tampers or defects. A change in the number of converters is only acceptable when it is allowed pursuant to an EO exemption.

Since January 1, 2009, ARB has required that all aftermarket catalytic converters installed in California as long has an EO number is on the catalytic converter.

If an EO number is not present and/or the wrong converter(s) is installed, the vehicle shall fail the catalyst visual inspection.

Buying most Aftermarket-Catalytic-Converters out side of California is illegal unless the catalytic converter has an approved EO number.

Note: Just because the catalytic converter has an EO number sold in California or in any other state the EO number must be looked up on every car. 

I have seen vehicles with an EO number but once it was looked up the exhaust shop installed the wrong one.  I personally had to call them and tell the shop manage because they wouldn't believe the customer. 


For OBDII Equipped Vehicles

inspectors shall use the EO number and corresponding part number to verify the part is approved for use on that specific vehicle configuration (e.g., year, make, model, engine, GVWR, fuel type, etc.). To conduct this verification, inspectors must check the ARB EO Aftermarket Catalytic Converter Database located on the ARB Web site. Each EO contains a catalog listing the applicable vehicles.

For Pre-OBDII Vehicles

inspectors shall use the EO number to verify the CAT falls within the correct vehicle category- PC-1, PC-2, T-1, T-2. Refer to ARB’s Web site for a separate Pre-OBDII EO Listing containing the EO numbers and corresponding vehicle categories. Inspectors are not required to check specific vehicle application using the series or part numbers. For older CATs without an EO label, use the general procedure described in the first paragraph above.


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