Despite CART teams sweeping the top 6 positions in the 2001 Indianapolis 500 and a highly competitive four-way points battle among Gil de Ferran, Kenny Brack, Hélio Castroneves, and Michael Andretti, headlines centered on a technological controversy regarding a turbo pop off valve that Honda and Ford had developed, prompting complaints by Toyota. When CART mandated changes in the valve to help equalize the competition, Honda successfully obtained an injunction barring the change, leading to all three manufacturers being upset. Toyota would announce it would move to the IRL for 2003 at the end of the season.