The California Air Resources Board has approved for sale two aftermarket replacement catalytic converters to meet the dramatically rising public demand prompted by the state's Smog Check program, 

Walker Manufacturing of Grass Lake, MI, and Echlin Inc. of Branford, CT, were granted permission to sell newly manufactured replacement converters after tests showed their use did not cause an increase in pollution levels, compared to use of factory original equipment. The newly approved aftermarket converters, with an estimated price tag of $100, are expected to provide a low-cost alternative to replacement of factory-original equipment that often costs $200 to $300 each. 

ARB officials estimate that sales of replacement catalytic converters have jumped 150 percent -- to 80,000 a year ---- since the Smog Check began last March. As car owners replace converters that have been illegally removed or poisoned through the illegal use of leaded gasoline, the public demand has outstripped the available supply at wrecking yards in some parts of the state. Under the Smog Check program, more than 20 million cars and light trucks in California's urban areas are tested once every two years to ensure that their pollution levels are within acceptable limits before their registration is renewed. Repairs for most cars that fail the test usually include minor adjustments, tune-ups or fixing of small components and are limited to a $50 cost. Those cost limits do not apply, however, to cars that fail the test because of tampered or modified anti-smog systems. In those cases, motorists must pay the full cost of restoring the anti-smog system to its factory-original design before the car's registration can be renewed. 

Motorists who destroy or remove catalytic converters risk more than increased repair costs under the Smog Check program. Catalytic converter damage can result in lower gas mileage and poorer driving performance, especially in newer models where the converter is linked electronically to the fuel and ignition systems. Also, illegal use of leaded gasoline in newer model cars can result in faster corrosion of exhaust systems and a need for nore frequent tune-ups, spark plug replacements and oil changes. 
The approvals granted to Walker and Echlin are temporary, until the ARB and Federal Environmental Protection Agency develop permanent methods of testing and certifying replacement catalytic converters. 
Models of both converters are expected to be available for most makes and models of post-1975 passenger cars and light trucks.