DETROIT (AP) - Volkswagen's plan to fix most of its 2-liter diesel engines that cheat on emissions tests includes a computer software update and a larger catalytic converter to trap harmful nitrogen oxide, and it may not hurt mileage or performance, according to dealers briefed by executives on the matter.

Limited details of the plan were made public last week at a regional dealer meeting in Newark, New Jersey, by Volkswagen of America Chief Operating Officer Mark McNabb.One dealer said the group was told that early testing of a small sample of repaired cars showed that the fix made "no discernable difference" in the cars' mileage, horsepower or torque.Both dealers said they were told that more testing was needed and that the plans still had to be approved by the U.S. Environmental Protection Agency and the California Air Resources Board.If the fixes don't hurt performance and mileage, that could be a big boost for Volkswagen, which last month agreed to spend up to $15.3 billion to settle consumer lawsuits and government allegations that its diesels cheated on U.S. emissions tests.The settlement included up to $10 billion that would go to over 475,000 owners of 2-liter VW or Audi diesels, giving them the choice of selling the cars back at the pre-scandal value or getting them fixed.A fix that is satisfactory to owners would entice more of them to go for repairs, saving VW money.