Volkswagen engineers have come up with a catalytic converter that could be fitted to around 430,000 cars in the United States as a fix for vehicles capable of cheating emissions tests, the German newspaper Bild am Sonntag reports. The converter would be fitted to cars with the first generation of the EA 189 diesel engine, the paper reported Sunday, without providing information on its sources.

A source familiar with the matter told Reuters the proposal for a technical solution that VW has drawn up includes a new catalytic converter system made in part from new materials.

Volkswagen has struggled to agree with U.S. authorities on a fix for vehicles fitted with the emissions test cheating devices, Reuters reported this week, showing how relations between the two sides remained strained four months after the scandal broke.

The fix would need to be approved by the U.S. Environmental Protection Agency, and Volkswagen CEO Matthias Mueller hopes to convince EPA officials at a meeting Wednesday in Washington, Bild am Sonntag added.