What the Federal Emissions Warranty Actually Covers
Federal rule 40 CFR 85.2103 makes the manufacturer repair certain emissions parts at no cost for 8 years or 80,000 miles, whichever comes first.
Most guides name three covered parts. The current rule names five groups. One of them is the battery in an electric or plug-in hybrid car.
The clock starts the day the car was first sold. Not the day you bought it.
Search for the federal emissions warranty and you get the same three parts every time. Catalytic converter, electronic control unit, on-board diagnostic device.
That list is old. It appears on EPA's own consumer FAQ page, which says those three are the only ones. The page was updated in June 2026, but the component list it points to is a fact sheet from October 2015.
The rule changed. Title 40 was amended in April 2024, again in June 2024, and again in February 2026. Here is what section 85.2103 says now.
What is covered, and for how long
Five component groups carry the long term on light-duty vehicles, light-duty trucks and medium-duty passenger vehicles.
| Component group | Term | Applies to |
|---|---|---|
| Catalytic converters, SCR catalysts and related parts | 8 yr / 80,000 mi | All |
| Particulate filters and traps | 8 yr / 80,000 mi | Gas and diesel |
| Exhaust gas recirculation parts | 8 yr / 80,000 mi | Diesel |
| Emission control module | 8 yr / 80,000 mi | All |
| EV and plug-in hybrid battery, plus charging and power delivery parts | 8 yr / 80,000 mi | Phase-in, see below |
Everything else in the emissions system gets 2 years or 24,000 miles.
Look at what moved. The on-board diagnostic device is no longer listed on its own. The rule now says emission control module. Particulate filters were added, and those show up on modern gas engines, not just diesels. Exhaust gas recirculation parts were added for diesels. And the battery entry did not exist in the old list at all.
There are two warranties, and they work differently
This is where most explanations blur together. The rule contains two promises. They are not triggered the same way.
| Feature | Performance warranty | Defect warranty |
|---|---|---|
| What sets it off | Car fails an approved emissions test | A covered part is defective |
| Extra condition | The failure has to expose you to a penalty under local, state or federal law | None |
| Standard term | 24 months / 24,000 mi | 2 years / 24,000 mi |
| Major components | 8 yr / 80,000 mi | 8 yr / 80,000 mi |
The performance warranty matters if your area runs emissions testing. Your car fails, you cannot register it, and the manufacturer has to fix the problem at no cost to you.
You do not have to wait until you are actually fined. The rule says a claim can be raised as soon as the failure starts a process under which you will face a penalty if the car is not repaired within some period of time.
The defect warranty needs no failed test. A defective covered part is enough.
If you bought the car used
The warranty follows the car, not the buyer. This is not an interpretation. It is written into the definitions.
Owner means the original purchaser or any subsequent purchaser of a vehicle.
That is section 85.2102. Wherever the rule says the manufacturer owes something to the owner, that includes you, the third person to own the car.
The period runs from the date the car was delivered to its first buyer. If it went into service as a demonstrator or a company car before it was sold, the clock starts on that date instead. It is measured in years and miles together and ends at whichever comes first.
Work an example. A car first sold in March 2020, now showing 55,000 miles. Those five component groups stay covered until March 2028 or 80,000 miles. You did not buy that coverage. It came with the car.
Electric and plug-in hybrid batteries
This entry is new and it has conditions.
The rule covers batteries serving as a Renewable Energy Storage System in electric and plug-in hybrid vehicles, along with the parts needed to charge the system, store energy and move the car.
Two carve-outs apply. On light-duty vehicles and trucks rated at or below 6,000 pounds GVWR, manufacturers can skip it before model year 2027. Above 6,000 pounds GVWR it stays optional until the vehicle is first certified to Tier 4 NMOG plus NOX bin standards, and no later than model year 2031.
So if you are looking at a used EV built before model year 2027, federal battery coverage is not automatic. Check the warranty booklet for that specific car.
Most brands offer 8 years or 100,000 miles on the battery as their own policy. That is their choice, not this federal floor, and terms vary.
One more thing worth knowing. The rule lets a manufacturer flag behavior that shortens battery life, such as exceeding towing capacity. But it also says the manufacturer should not treat something as improper use if the car could have been designed to prevent it. Evidence is generally limited to onboard data logging.
What a dealer cannot refuse over
Section 85.2104 lists five things that can never be grounds for denial. The rule says in no case may a manufacturer deny a claim based on:
- Warranty work or predelivery service done at a facility the manufacturer authorized
- Emergency work to fix an unsafe condition caused by the manufacturer, as long as you put the car back in shape promptly
- An uncertified part or a missed maintenance step that had nothing to do with why the car failed
- Anything the manufacturer itself caused
- Fuel that is commonly sold in your area, unless the manual warns against that fuel and you had a normal way to know
The third one comes up constantly. You had the oil changed at a local shop, the catalytic converter failed two years later, and the dealer points at the oil change. Those two things are not connected. That is not a valid denial.
There is also a limit on what the dealer can demand from you. The manufacturer can ask for maintenance records only for items it has an objective reason to think were skipped, and only where skipping them could have caused the car to exceed standards. Your own written statement counts as evidence if you did the work yourself, as long as you can show you used the right parts.
Certified aftermarket parts
A certified aftermarket part cannot be used to deny a performance warranty claim. That is section 85.2105, and it says so directly.
For an uncertified part the manufacturer can deny, but it has to work for it. The rule requires a written document to you that establishes a causal link between the emissions failure and that part, explains what removing it would fix, and lists every piece of objective evidence behind the decision. That evidence has to be available to you or to EPA on request.
Your owner's manual is also required to carry a line, in boldface, saying that emissions parts may be serviced or repaired by any repair shop or individual using any certified part. If a service writer tells you otherwise, open the manual.
The 30-day clock
Once you hand over the car, the manufacturer has 30 days.
Section 85.2106 gives it that long, at most, to reach a final decision from the moment the car is first presented for repair. If state or local law gives you a shorter window to get the car fixed without penalty, the shorter window controls. Delays you asked for do not count, and neither do delays outside the manufacturer's control.
Inside that window the manufacturer has to do one of three things. Tell you it will honor the claim. Give you a written explanation of the denial. Or, if the denial turns on an uncertified part, give you the written explanation described above.
If the shop where you dropped the car cannot handle the claim, it has to forward the claim to someone at the manufacturer with authority to decide. You can waive that in writing. Do not waive it.
Miss the deadline and the consequences are specific. Section 85.2106 says the manufacturer becomes responsible for repairing the covered items free of charge. Section 85.2107 goes further. You get to have the work done at the manufacturer's expense by any repair facility you choose.
That second part matters. It is not just free repair at the same dealer. It is free repair somewhere else.
Why two EPA documents disagree
Both are published by EPA. They do not match.
| Feature | EPA consumer FAQ | 40 CFR 85.2103 |
|---|---|---|
| Components listed | Three, called the only ones | Five groups |
| Underlying document | Fact sheet EPA-420-F-15-035, October 2015 | Text as amended February 2026 |
| Page date | Updated June 10, 2026 | Current as of June 30, 2026 |
We are not in a position to say which one controls a given dispute. What we can say is that the rule has been amended three times since 2024 and the FAQ list rests on a document from 2015.
EPA's FAQ makes a fair point of its own. Vehicle technology keeps changing, some emissions parts will not appear on any published list, and the fuller list for your car is in the owner's manual and warranty booklet.
Check this yourself
- Open eCFR and search for 40 CFR 85.2103.
- Read paragraph (d)(1). Count the groups against the table above.
- Read paragraph (b) for how the period is measured.
- Read 85.2102 for the definition of owner.
- Find the in-service date for the car and count forward eight years.
- Open the warranty booklet and compare. Brands can offer more than the floor, and California-certified cars follow additional state rules.
Where to call
Government and manufacturer channels only. We do not list private businesses.
| If you need to | Contact | Notes |
|---|---|---|
| Report a warranty violation | complianceinfo@epa.gov | Director, Compliance Division, EPA, 2000 Traverwood Dr., Ann Arbor, MI 48105, Attention: Warranty |
| Report a safety defect | 888-327-4236 | NHTSA Vehicle Safety Hotline, Mon to Fri, 8 a.m. to 8 p.m. ET, English and Spanish |
| Same, hearing impaired | 888-275-9171 | NHTSA TTY line |
| Check open recalls by VIN | nhtsa.gov/recalls | Free, covers the last 15 years |
| Dispute a denied claim | Manufacturer customer assistance | Number is in your owner's manual |
What this page does not tell you
This is the federal floor. Brands can offer more and several do. California-certified cars follow extra state requirements with longer terms on some parts.
It also settles no individual claim. Whether a specific failure qualifies gets decided case by case, and coverage can be denied where the manufacturer proves abuse, bad installation work, or unscheduled work that disabled an emissions part.
What you get here is the current text, the date we read it, and where to check it.
Sources
- 40 CFR 85.2102, 85.2103, 85.2104, 85.2105, 85.2106, 85.2107, 85.2109. eCFR, title 40 current as of June 30, 2026. Retrieved July 27, 2026.
- Amendment history for 85.2103: 89 FR 28152, April 18, 2024. 89 FR 50234, June 13, 2024. 91 FR 7759, February 18, 2026.
- EPA, Frequent Questions related to Transportation, Air Pollution, and Climate Change. Page last updated June 10, 2026. Retrieved July 27, 2026.
- EPA fact sheet EPA-420-F-15-035, October 2015, referenced by the FAQ above.
- NHTSA, Contact Us. Retrieved July 27, 2026.
- Authority: Clean Air Act sections 203, 207, 208 and 301(a). 42 U.S.C. 7522, 7541, 7542, 7601(a).