How to look up a CARB EO number
How to Look Up a CARB EO Number
Quick answer: Find the EO number on the part's label or paperwork, then open CARB's aftermarket parts lookup and pick the type of part. Read the full EO record; the number is only the starting point.
Step 1: Find the number
CARB's exemption procedures require a product information label with each exempted device, installed under the hood where it's readily visible. The label shows the product name as listed on the EO, the CARB EO number, and the manufacturer's name and contact information. Manufacturers may add one type of extra number: reference numbers, device numbers or kit part numbers. That one type can include several numbers.
BAR's Smog Check Manual adds that aftermarket parts labels are affixed or stamped on the part, or installed near it when that isn't practical.
Aftermarket catalytic converters follow their own format: the label shows the EO number, the manufacturer's part number, and the month and year of manufacture.
No label in sight? Check your receipt, the box, the instructions, or the manufacturer's catalog, which BAR's manual names as one reference for EO information.
Step 2: Choose the right CARB lookup
CARB's aftermarket parts lookup page asks you to select a type of part: performance and add-on parts, catalytic converters, motorcycles, auxiliary fuel tanks, or alternate fuel retrofit systems.
Step 3: Search and open the record
Performance and add-on parts: CARB's database has three drop-down filters, each with its own search box: Executive Order Number, Manufacturer and Device Type, plus a Clear Filters button. Results show the EO, the file (a View PDF link), the EO date, the manufacturer name and the device; select an EO to see the part detail. There's no make, model, year or engine search, so search by EO number, manufacturer or device type, then read the EO for the vehicles it lists.
Catalytic converters: CARB's Aftermarket Catalytic Converter Database has two tabs. Vehicle Search uses Make, Model Year, Model and Engine Size. EO Search uses ARB EO Number.
Step 4: Read the whole record
According to BAR, CARB's EO parts listings include the parts covered by each EO number, the part manufacturers, and the vehicles the parts can be installed on. They may also describe modifications necessary for installing a part. Guide 10 walks through reading the vehicle list.
Step 5: Save what you found
Save the EO and note the date you looked. If you're stuck, CARB's helpline is (800) 242-4450 or helpline@arb.ca.gov.
What Showgone can and can't do here
Showgone gives you a place to store the EO number, label photo and your saved copy of the EO, plus a link to read the EO at CARB. Showgone isn't CARB, BAR, the DMV or a smog station, and your Showgone record isn't an official certificate. CARB issues EOs, and the Smog Check inspector decides at inspection.
Add this part to your free Showgone garage.
Not legal advice.
Sources
- CARB: Procedures for Exemption of Add-On and Modified Part(s) for On-Road Vehicles/Engines (adopted June 29, 2021), Section VIII
- BAR: Smog Check Manual (April 2025), Sections 1.3.1 and 1.3.2, Appendix C
- CARB: Aftermarket parts lookup
- CARB: Aftermarket, Performance, and Add-On Parts Regulations (database page)
- CARB: Aftermarket Catalytic Converter Database (information page)
- CARB: Aftermarket, Performance, and Add-on Parts (contact information)
Date checked: 2026-10-20