The Bush administration announced yesterday that it has reached a settlement in a Clean Air Act lawsuit against Toyota Motor Corp. that will require the giant automaker to spend about $34 million to implement antipollution measures.

In a joint announcement, the Justice Department and the Environmental Protection Agency said Toyota has agreed to spend about $20 million to retrofit as many as 3,000 diesel vehicles, including older school buses and municipal buses, with modern antipollution devices such as catalytic converters. They said Toyota also has agreed to accelerate its compliance with a new EPA emissions regulation that will affect about 1.4 million vehicles manufactured between 2004 and 2006 at a cost of about $11 million.

Toyota has agreed to pay a $500,000 civil penalty to settle the lawsuit, according to the announcement.

Irv Miller, a Toyota spokesman, said that the company had not been officially notified of a settlement and that he could not comment on the government announcement until the company was notified.

The lawsuit, filed in U.S. District Court in Washington, involved several Toyota models from the 1996 to 1998 model years. The government alleged that in documents certifying the vehicles' compliance with Clean Air Act emissions standards, Toyota failed to disclose limitations in a diagnostic system that is supposed to warn drivers of fluid leaks that can cause pollution, according to the announcement.

The settlement announced yesterday does not require Toyota to do anything with the 2.2 million vehicles that triggered the lawsuit. An EPA official said this was because "there is nothing wrong with the cars," but that Toyota "didn't follow the proper certification process" in asserting that the vehicles met emissions standards.

Instead, under the settlement, Toyota has agreed to retrofit diesel vehicles that it does not manufacture as a step toward reducing overall pollution levels in the country. An EPA official likened this to "doing community service."

Under current EPA regulations, Toyota would not be required to meet a new "near-zero" evaporative emissions standard in its 2004 to 2006 models, but has agreed to do so as part of the settlement, the announcement said.

In two other related announcements yesterday, the EPA said it has filed a notice of Clean Air Act violations against East Kentucky Power Cooperative's coal-fired power plant in Mayesville, Ky. Roy Palk, the company's chief executive officer, said East Kentucky's lawyers are preparing a response to the notice.

EPA also announced that Caterpillar Inc., has paid $41.3 million in fines under a 1998 consent decree stemming from the manufacture of diesel engines that failed to meet emissions standards.