Mazda Miata Recall

Introduction - This web page provides information on the recall of 2001 and 2002 Mazda Miata cars. Many of these cars could exceed federal emission standards because of inadequate emission control when the vehicle is started cold. EPA discovered the potential emission compliance problem after testing the Miatas at its National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan. EPA conducts random testing of vehicles in use to assure emission compliance.

Mazda Motor Corporation

Models Affected:
2001 and 2002 model year Mazda Miata

Number of Vehicles Sold:
32,018 vehicles, nationwide

Mazda Motor Corporation

Emissions Problem:
Many of the vehicles may fail the EPA Non-Methane Organic Gases (NMOG) standard as discovered in the EPA recall surveillance testing program. NMOG is the sum of all organic pollutants excluding methane. NMOG is a measure of emissions that are precursors of ozone. Mazda's analysis of the cause of the failures concluded that the failures were the result of higher than anticipated emissions at startup. Because the 2001 and 2002 vehicles are identical, the problem occurs in both model years.

There will be no indication of a problem to the driver or to a service technician.

Mazda is voluntarily recalling all 2001 and 2002 Miata model vehicles and replace the Central Processing Unit (CPU) with one that incorporates new cold start calibrations. The new calibrations will affect air-fuel ratio under cold conditions, idle speed, ignition timing, and valve overlap. The average reduction in NMOG emissions are expected to be 26%. Mazda says there will be no adverse effect on vehicle performance and fuel economy. The CPUs removed from the vehicles will be returned to Mazda and re-calibrated, to be later installed on other vehicles as part of the fix. Mazda plans to phase in this recall by sending owner letters by regions over a period of time to assure a ready supply of CPUs. For more information on the regions and timing, contact Mazda Customer Service at (800) 222-5500, or e-mail at


Recall Program Background
Vehicle manufacturers are required to design and build their vehicles to meet emission standards for the useful life of the vehicle specified by law. Under Section 207 of the Clean Air Act, if EPA determines that a substantial number of vehicles in a class or category do not meet emission standards in actual use even though they are properly maintained and used, EPA can require the manufacturer to recall and fix the affected vehicles.

Most recalls are initiated voluntarily by manufacturers once a potential noncompliance is discovered. Some voluntary recalls are directly influenced via EPA in discussions with manufacturers. Some voluntary actions to remedy problems are extended warranty campaigns (such as the one described below) rather than direct recalls to repair all vehicles. EPA agrees to extended warranty campaigns when there is a high likelihood that owners will seek repair based on overt failure indications.

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