United States Air and Radiation EPA420-F-96-020
Environmental Protection Agency

Office of Mobile Sources
EPA Environmental Fact Sheet


Federally required emission control warranties protect you, the vehicle owner, from the cost of repairs for certain emission related failures that result from manufacturer defects in materials and workmanship or that cause your vehicle to exceed federal emission standards.
Manufacturers have been required by federal law to provide emission control coverage for vehicles since 1972. There are two federal emission control warranties discussed in this fact sheet:
"Performance Warranty" and
(B) "Design and Defect Warranty". This fact sheet explains each warranty in detail, provides you with a list of some of the parts covered under these warranties, explains the procedures for making an emissions warranty claim, and answers some of the most commonly asked questions about emissions warranties.
Finally, we will give you some tips on how to prevent future emission-related failures and maintain the longevity of your vehicle's engine.


The Performance Warranty covers repairs which are required during the first 2 years or 24,000 miles of vehicle use because the vehicle failed an emission test. Specified major emission control components
are covered for the first 8 years or 80,000 miles. If you are a resident of an area with an Inspection and Maintenance (I/M) program that meets federal guidelines, you are eligible for this warranty protection provided that:

* Your car or light-duty truck fails an approved emissions test; and
* Your vehicle is less than 2 years old and has less than 24,000 miles (up to 8 years/80,000 miles for certain components); and
* Your state or local government requires that you repair the
vehicle; and
* The test failure does not result from misuse of the vehicle or a failure to follow the manufacturers' written maintenance instructions; and
* You present the vehicle to a warranty-authorized manufacturer representative, along with evidence of the emission test failure, during the warranty period.
During the first 2 years/24,000 miles, the Performance Warranty covers any repair or adjustment which is necessary to make your vehicle pass an approved, locally-required emission test and as long as your vehicle has not exceeded the warranty time or mileage limitations and has been properly maintained according to the manufacturer's specifications.


The Design and Defect Warranty covers repair of emission related parts which become defective during the warranty period. The Design and Defect warranty for model year 1995 and newer light-duty cars and trucks is outlined below:

Design and Defect Warranty Coverage for 1995 and newer light-duty vehicles:

* Emission control and emission related parts are covered for the first 2 years or 24,000 miles of vehicle use; and

* Specified major emission control components are covered for the first 8 years or 80,000 miles of vehicle use.

According to federal law, an emission control or emission related part, or a specified major emission control component, that fails because of a defect in materials or workmanship, must be repaired or replaced by the vehicle manufacturer free of charge as long as the vehicle has not exceeded the warranty time or mileage limitations for the failed part.

Design and Defect Warranty coverage may vary depending on the type of vehicle you have (e.g., heavy-duty trucks, motorcycles or recreational vehicles have different time and mileage requirements).
To determine the length of warranty coverage that applies to your vehicle, look for the emissions warranty information in your owner's manual or warranty booklet. If you own a California vehicle, you may be entitled to additional warranty coverage.

The owner's manual or warranty booklet will also provide you with guidance on the procedures for obtaining warranty coverage. If you have questions about the emissions warranties on your vehicle or need help in filing a warranty claim, contact your local car dealer or the manufacturer's zone or regional representative listed in your owner's
manual or warranty booklet.

What Emission Control and Emission Related Parts Are Covered by The Design and Defect Warranty?

An emission control part is any part installed with the primary purpose of controlling emissions. An emission related part is any part that has an effect on emissions. Listed below are some examples of parts or systems which fall under these definitions. A more complete list can be found in your owner's manual/warranty booklet.

If any of the parts listed below fail to function or function improperly because of a defect in materials or workmanship, causing your vehicle to exceed federal emission standards, they should be repaired or replaced under the emissions warranty if your vehicle is less than 2 years old and has been driven less than 24,000 miles.
One manufacturer may use more parts than another, so the following list is not complete for all vehicles.

Exhaust Gas Conversion Systems
oxygen sensor thermal reactor
catalytic converter dual-walled exhaust pipe

Exhaust Gas Recirculation System
EGR valve thermal vacuum switch
EGR solenoid EGR spacer plate
EGR backpressure transducer Sensor and switches use to control EGR flow

Evaporative Emission Control System
purge valve fuel filler cap
purge solenoid vapor storage canister and filter
Positive Crankcase Ventilation (PCV) System
PCV valve PCV solenoid
Air Injection System
Air pump diverter, bypass, or gulp valve
reed valve anti-backfire or deceleration valve

Early Fuel Evaporative (EFE) System
EFE valve thermal vacuum switch heat riser valve

Fuel Metering System

electronic control module (unit) or EFI air flow meter, computer command module or mixture control unit, deceleration controls, electronic choke, fuel injectors, fuel injection units and fuel altitude compensator sensor, bars or rails for EFI or TBI systems, mixture settings on sealed fuel mixture control solenoid, diaphragm or other systems, fuel metering components that achieve closed/other feedback control sensors/loop operation switches and valves

Air Induction System
thermostatically controlled air cleaner, air box
Ignition Systems
electronic spark advance timing advance/retard systems,
high energy electronic ignition

Miscellaneous Parts
hoses, gaskets, brackets, clamps and other accessories used in the above systems


These are examples of other parts of your vehicle which have a primary purpose other than emissions control but which nevertheless have significant effects on your vehicle's emissions.
If any of these parts fail to function or function improperly, your vehicle's emissions may exceed federal standards. Therefore, when any of the parts of the following systems are defective in materials or workmanship and have failed in a way that would be likely to cause your vehicle's emissions to exceed federal standards, they should be repaired or replaced under the emissions warranty:

Fuel Injection System
fuel distributor
Air Induction System
turbocharger intake manifold

Exhaust System

exhaust manifold
Ignition System
distributor spark plugs
ignition wires and coil

Miscellaneous Parts
hoses, gaskets, brackets, clamps, and other accessories used in the above systems.

What Are Specified Major Emission Control Components?

There are three specified major emission control components, covered for the first 8 years or 80,000 miles of vehicle use on 1995 and newer vehicles:

* Catalytic converters.
* The electronic emissions control unit or computer (ECU).
* The onboard emissions diagnostic device or computer (OBD).

Catalytic converters are critical emission control components that have been installed on most cars and trucks manufactured since 1975. Since engines don't burn fuel completely during the combustion process, the exhaust contains a significant amount of harmful pollutants such as carbon monoxide, hydrocarbons, and oxides of nitrogen.
The catalytic converter aids the conversion of these pollutants to less harmful substances such as carbon dioxide, water
vapor, nitrogen, and oxygen before the exhaust is expelled into the environment.

The electronic emissions control unit or computer monitors certain powertrain functions and controls various operating parameters to help the vehicle run efficiently and with the lowest possible emissions. Ignition, transmission function, air injection, exhaust gas recirculation (EGR), engine operating temperature and fuel system parameters are some of the systems monitored and/or controlled by the electronic emissions control unit.

The onboard emissions diagnostic device monitors the operation of a vehicle's emission control system and alerts the driver with a dashboard light when malfunctions occur. The system will record where the problem is occurring and assist automotive technicians in diagnosing and repairing emission control malfunctions.
Since some emission control malfunctions do not have an adverse effect on vehicle performance, they can go undetected by the driver for quite some time.
The onboard diagnostic device will help catch malfunctions early, preventing a significant output of harmful exhaust emissions from your vehicle, and possibly in time to be covered by the emissions control warranty. Often this "device" is part of the electronic control unit mentioned above.

In the future, there may be other parts or components that qualify for this coverage. Check your owner's manual or warranty book for possible additional coverage.

How Long Do the Emissions Warranties Apply to Individual Parts of My Vehicle?

For 1995 and newer model year vehicles, emission control and emission related parts are warranted for the first 2 years or 24,000 miles of vehicle use. Specified major emission-control components are warranted for the first 8 years or 80,000 miles of vehicle use.

Parts with a stated replacement interval, such as, "replace at 15,000 miles or 12 months," are warranted up to the first replacement point only.

How Do I Know Whether I Am Entitled to Coverage Under the Emissions Warranties?

If you or a qualified automotive technician can show that an emission control or emission related component, or a specified major, emission-control component, is defective, the repair or replacement of the part is probably covered under the Design and Defect warranty.
If your vehicle failed a federally approved emissions test and has not exceeded the time and mileage limitations for the Performance warranty, any repairs or adjustments necessary for your vehicle to pass should be covered by the manufacturer if the failure was not caused by improper maintenance or abuse.
When you believe you have identified a defective part, or your vehicle fails an emission test, you should follow the procedures for making a warranty claim as identified by the manufacturer in your owner's manual or warranty
booklet. When taking your vehicle in to have repairs performed under the Performance Warranty, be sure to have with you a copy of the I/M test report as proof of your emissions test failure.

May I Have My Regular Repair Facility Perform Warranty Repairs?

If you plan to have the manufacturer pay for a repair under either of the emissions warranties, you must take the vehicle to a facility authorized by the vehicle manufacturer for repair to give them the opportunity to diagnose and repair it.
Note that if your regular repair facility is not authorized by the vehicle manufacturer, they are not obligated to advise you of parts that are covered under warranty. Before giving your automotive technician the "go ahead" to perform repairs, check your owner's manual/warranty booklet for possible warranty coverage.

Do the Emissions Warranties Apply to Used Vehicles?

Yes. It does not matter if you bought your vehicle new or used from a dealer or anyone else. As long as the vehicle has not exceeded the warranty time or mileage limitations, these warranties apply.

Before buying a used vehicle, be sure that all of the emission control components as originally installed by the manufacturer are present and functioning properly.
If emission control components are missing or have been tampered with, or the configuration of the exhaust system has been changed, the emissions warranties on this vehicle may be void. In addition, if you live in an area with an I/M program, the vehicle will probably not pass inspection and you will incur the expense of parts or repairs necessary for the vehicle to pass.

Can Any Portion of An Emissions Warranty Repair Be Charged to Me?

If you have valid warranty claim, you cannot be charged for any costs associated with the diagnosis or repair of the problem, including labor charges, parts, or miscellaneous items that are necessary to complete the repair. For example, if a manufacturer agrees to replace a catalytic converter under the emissions warranty, you should not be charged for the diagnosis of the bad converter, or any pipes, brackets, adjustments, or labor needed to complete the replacement.

What Reasons Can the Manufacturer Use to Deny a Warranty Claim?

If your vehicle is within the age and mileage limits for the applicable emissions warranty, the manufacturer can only deny coverage if evidence shows that you have failed to properly maintain and use your vehicle, causing the part or emission test failure. Some examples of misuse and mal maintenance include the following:

* vehicle abuse such as off-road driving or overloading; or

* tampering with emission control parts or systems, including removal or intentional damage of such parts or systems; or

* improper maintenance, including failure to follow maintenance schedules and instructions specified by manufacturer, or use of replacement parts which are not equivalent to the originally installed parts.

What Should I Do If My First Attempt to Obtain Warranty Coverage Is Denied?

If your first attempt to receive emissions warranty coverage is denied, you should do the following:

1) Ask for a detailed explanation, in writing as to why emissions warranty coverage was denied; and

2) Ask for the name(s) of the person(s) involved in the decision to deny coverage, including anyone from the manufacturer's regional or zone office; and

3) Ask for the name(s) of the person(s) with the manufacturer you should contact to appeal the denial of coverage under the emissions warranty.

4) Contact and, if necessary, write to the person mentioned above requesting coverage and giving the basis for your request. Repeat and continue the appeal process until you are satisfied or have exhausted all means of appeal.

What If the Dealer Claims That My Vehicle Can Pass the I/M Test Without Repair?

The law does not require that you fail every I/M test in order to trigger the warranty.
If a valid test shows that you have an emission problem or there is a defective part, you should get it fixed, while your vehicle is still within the warranty period. Otherwise, you might fail a future test because of the same problem and have to pay for the repair yourself.
If you doubt your original test results or the dealer's results or diagnosis, you can always get another opinion from another dealer or your I/M program.

How Can Maintenance Affect My Emission Warranty Coverage?

Performance and the cost of scheduled maintenance are your responsibility. You may either perform scheduled maintenance yourself or have a qualified repair facility perform it for you.

If a part fails as a direct result of your vehicle not being properly maintained or being used in a manner inconsistent with the manufacturer's recommendations, or a part fails as a result of the vehicle being involved in an accident, the manufacturer may not be required to repair or replace the failed part under warranty.
For example, failure to replace the spark plugs at the intervals specified in the maintenance schedule can lead to misfiring and eventual damage to your catalytic converter - a very expensive part to replace.
If the maintenance is not performed properly as recommended, the manufacturer may deny warranty coverage.

To ensure maximum air pollution reduction from the emission control system, as well as to ensure continued warranty coverage, better gas mileage and performance, and longer vehicle life, you should have all maintenance performed as recommended by the manufacturer's schedule. A list of scheduled maintenance for your vehicle can be found in the owner's manual or warranty booklet.

Do I Have to Show Any Maintenance Receipts Before I Can Make an Emissions Warranty Claim?

No. Proof of maintenance is not required in order to obtain coverage under the emissions warranty if an emission control or emission related component, or a specified major emission control component, is found to be defective in materials or workmanship.
However, when it is likely that the lack of proper maintenance has caused the particular part to fail, you may be asked to show that scheduled maintenance was performed.

If you perform scheduled maintenance yourself, you should keep a detailed log of work performed and any receipts for parts purchased to perform the maintenance. In some instances, you may be asked to qualify your ability to perform such maintenance. Vehicles should always be maintained according to manufacturers' specifications.

Are Dealers the Only Persons Allowed to Perform Scheduled Maintenance Recommended by the Manufacturer?

No. Scheduled maintenance may be performed by anyone who has the knowledge and ability to perform the maintenance and repair. You may even maintain the vehicle yourself, as long as the maintenance is
performed according to the manufacturer's instructions provided with the vehicle.

For your protection, before taking your vehicle to a repair facility to have any maintenance performed, check your maintenance booklet and make a list of the scheduled maintenance to be performed at that time.
We suggest that you present this list to your auto technician as opposed to merely asking for a "tune-up" or a "12,000 miles servicing." Your receipt should list all the maintenance performed and should be kept for your records.

If you maintain the vehicle yourself, you should keep receipts for parts and a maintenance log to verify your work.

If I Need Replacement Parts, Must I Use the Vehicle Manufacturer's Parts Only?

No. A manufacturer cannot require the use of any specific brand of parts in the maintenance of your vehicle. However, the manufacturer can require you to use parts that are of equal quality to the original parts.

If I Buy a Used Vehicle, How Do I Know Whether It Has Been Maintained According to The Maintenance Schedule?

The best way to learn whether the vehicle has been maintained according to its schedule is to ask the seller for receipts proving that all of the scheduled maintenance was performed. Having the receipts on hand will provide necessary evidence if the question of maintenance arises when considering repairs under warranty. To
prevent any loss of your vehicle's emission performance, you should continue to follow the maintenance schedule in the owner's manual or warranty booklet.

If the seller does not have the owner's manual, warranty booklet or maintenance schedule, you can obtain them from the manufacturer.

How Will I Know If My Claim Has Been Accepted As Valid?

After you present your vehicle for a Performance Warranty claim, the manufacturer has 30 days to either repair the vehicle or notify you in writing that the claim has been denied. If you are making a Performance Warranty claim and your I/M program imposes a shorter repair deadline, the manufacturer must meet the deadline.
Because of the significance of these deadlines, you should get written verification from the dealer showing that they acknowledge the date by which repairs must be made.

There are no specific requirements for Defect Warranty claims, however, manufacturer responses should be made within a reasonable time period.

What Happens If the Manufacturer Does Not Respond to My Performance Warranty Claim Within the 30-Day Deadline?

You may agree to extend the deadline, or it will be automatically extended if the delay was beyond the control of the manufacturer.
Otherwise, a missed deadline means the manufacturer forfeits the right to deny the claim.
You may then have the repair performed at a facility of your choice, at the manufacturer's expense. (This requirement only applies to Performance Warranty claims.)

What Do I Do If the Manufacturer Will Not Honor What I Believe to Be a Valid Emissions Warranty Claim?

If you believe the manufacturer has not honored a valid claim and your vehicle has not exceeded the time and mileage limitations, you should contact an authorized warranty representative and follow the procedures outlined in your owner's manual or warranty booklet.
If the authorized dealer denies your warranty claim, contact the manufacturer's regional or zone office for further assistance. If you are still not satisfied, follow the appeals procedure outlined in your
manual or warranty booklet.

Of course, you are entitled to pursue any independent legal actions you consider appropriate to obtain coverage under the emissions warranties. In addition, the Environmental Protection Agency (EPA) is authorized to investigate the failure of manufacturers to comply with the terms of these warranties.

If you have followed the manufacturer's procedures (including those for appeals) for making a warranty claim as set out in your owner's manual or warranty booklet, have received a written denial and you are not satisfied with the manufacturer's determination, you may submit a letter to EPA at the following address.
It should provide details of the situation including the basis for the claim, a copy of the written denial, copies of your letters to the manufacturers, and copies of any receipts for emission control parts and repairs you have paid for:

U.S. Environmental Protection Agency
Vehicle Programs & Compliance Division (6405J)
Attn: Warranty Complaints
401 M Street, SW
Washington, DC 20460

Other sources of assistance may be your local or State consumer protection agency or office of the Attorney General. You also should be aware that low-cost or free legal assistance may be available through a local legal aid office, the State bar association, or a law school clinic staffed by law students.

In Summary

If an emission control or emission related part, or a specified major emission control component is defective, or if your vehicle fails an I/M test, and your vehicle is within the time and mileage limitations for emissions warranty coverage:

* present a warranty claim to an authorized warranty representative.

If your warranty claim is denied:
* Ask for the reason for denial, in writing.
* Follow the appeal procedures in your owner's manual. If you are not satisfied with the manufacturer's decision:
* Contact the EPA, which will investigate the denial of a valid emissions warranty complaint.

Keep This With Your Vehicle for Future Reference.

Team ZR-1
True Custom Performance Tuning