Emissions reference
What the EMIS code on a part means
Some of our parts carry an emissions category code. Here is what each one means, in the words of the people who set it, so you can decide what is right for your bike before you order.
The five categories
The code comes from a system developed by SEMA, the Specialty Equipment Market Association, and is assigned by the part’s own manufacturer. Drag Specialties prints it in the EMIS column of its catalog. Every category below is quoted exactly as Drag publishes it.
“This Product is covered under a CARB EO and is legal for sale and use in all 50 states.”
- Sales
- No USA Territory Restrictions.
“This product is covered under a SEMA Certified Emissions certification or has otherwise met the requirements of the EPA’s Tampering Policy and is legal for sale in states that do not mandate an EO.”
- Sales
- Blocked from sales into California.
“This product is not legal for street use on an emissions-controlled vehicle. It may be used on dedicated competition or pre-pollution-controlled vehicles only.”
- Sales
- “Blocked from sales in ALL states unless dealer signs acknowledgment of dealer’s obligation to ensure sales or installation of such parts are on ‘Competition Use’ only vehicles and not for highway use.”
“This product does not require an EO in California. By nature of its design, it is legal for sale and use in all 50 states. Replacement parts included.”
- Sales
- No USA Territory Restrictions.
“Product not subject to emissions control regulations.”
- Sales
- No USA Territory Restrictions.
Worth knowing about category 3
A category 3 code does not always mean the manufacturer declared the part race-only. Drag prints this note in the category 3 row:
“Products for which vendors did not supply classification information are by default coded as ‘3.’”
So a 3 can mean the part really is competition-use only, or it can mean the manufacturer simply filed no classification. The catalog does not distinguish between the two. If a specific part matters to you, ask us and we will chase the manufacturer for an answer rather than guess.
The four terms behind the codes
These are the definitions Drag Specialties publishes on page 5. The first three describe parts that are, in the catalog’s own words, not illegal for sale in California under CARB regulations. The fourth is federal only.
CARB E.O.
California OKAn Executive Order issued by the California Air Resources Board for a specific part on specific bikes.
“An Executive Order constitutes an exemption by CARB from CA Vehicle Code 27156 and 38391, for sale of the part number for the make/model/year fitment(s) specified in the Executive Order.”
Replacement Part
California OKA part that stands in for an original equipment emissions part without changing how it behaves.
“Any aftermarket part intended to replace an original equipment emissions-related part and which is functionally identical to the original equipment part in all respects which in any way affect emissions (including durability), or a consolidated part.”
Qualified Manufacturer Declared Replacement Part
California OKThe same thing, where the manufacturer has put the assessment in writing.
“…evaluated and declared by the manufacturer to meet this definition and carry this categorization and designation label. This manufacturer has declared in writing that it has documentation, based upon sound engineering judgment, indicating the replacement part does not reduce the effectiveness of any required emission control device and it does not cause the modified vehicle/engine/equipment to exceed applicable emissions standards for that make/model/year fitment(s) advertised.”
Qualified Manufacturer Declared 49-State Federal Emissions Compliant Part
Not CaliforniaMeets the federal EPA standard. The catalog labels this one, in parentheses, not legal for sale or use in California.
“Any aftermarket part intended to replace an original equipment emissions-related part and that meets all EPA emission regulations by installing the element of design in all emissions-related respects to the certified configuration of the vehicle, engine, or piece of equipment. This manufacturer has declared in writing that it has fully documented the emissions testing of an appropriate test vehicle…”
The part most riders miss
An E.O. covers a part number and a fitment
“CARB legal” is not a property a part carries around with it. An Executive Order names the part number and the make, model and years it covers. The same part can be covered on one bike and not on another.
So when you are checking whether something is street legal where you live, the question is not just “does this part have an E.O.” but “does its E.O. cover my year and model.”
What CARB actually restricts
California’s rule is about parts that change how the factory emissions equipment performs. Drag states it this way:
“The California Air Resources Board (‘CARB’) does not permit the use of aftermarket emissions-related part(s) that alter the performance of OEM emissions-related devices unless CARB has issued an Executive Order, other than on racing vehicles on closed courses.”2026 Drag Specialties FatBook, p. 5
The catalog then names the kinds of products it has in mind. This list is not exhaustive, and it is worth reading because a few entries surprise people:
- Exhausts
- Catalytic converters
- Oxygen sensors
- Fuel/air controller modules
- Air filter kits
- Camshafts
- O2 eliminators
- Carburetors
- Jet kits
Camshafts are on that list explicitly. A cam or camchest kit is an emissions-related part in CARB’s eyes, which is why you will see emissions notes on engine internals and not just on pipes.
“Race Only” parts
Category 3 points back to this note. It is the strongest language in the catalog and it is worth reading in full before you buy anything carrying that code.
“Parts designated as ‘Race Only’ are for use only on vehicles used for competition racing and are not for use on vehicles registered for use on public roads. Sale and/or installation of ‘Race Only’ parts in any way inconsistent with this warning is prohibited and may result in enforcement by the U.S. EPA under the federal Clean Air Act. ‘RACE ONLY’ PARTS ARE NOT LEGAL FOR SALE IN CALIFORNIA ON ANY POLLUTION CONTROLLED MOTOR VEHICLES.”2026 Drag Specialties FatBook, p. 5
If you are building a dedicated race bike or a pre-emissions machine, these parts exist for you. If the bike is registered and ridden on the road, they are not the right choice, and we would rather tell you that before you order than after.
Check it yourself
Rules differ by state and they change. These are the primary sources, not summaries of them.
About this page
Everything quoted here comes from the 2026 Drag Specialties FatBook, pages 5 through 7, which in turn reflects definitions set by CARB, the US EPA and SEMA. We have quoted rather than paraphrased on purpose.
MetalCore Harley Supply is a parts retailer, not a law firm, and nothing on this page is legal advice or a statement about whether a particular part is legal for your bike in your state. Emissions rules vary by jurisdiction and change over time. Check your own state and local regulations, and the manufacturer’s information for the specific part, before you buy or install.
Questions about a specific part number? Get in touch and we will find out what we can from the manufacturer.