Castroneves switched to the IRL from the 2002 season since Marlboro wanted Penske to focus on the American market. Penske changed engine manufacturers from Oldsmobile to Chevrolet for its Dallara IR-02 car. At Phoenix for the season's second race, he won from pole position after passing his teammate de Ferran on the 183rd lap. Castroneves' season highlight was the Indianapolis 500, which he won in controversial circumstances. With 1 laps remaining, CART driver Paul Tracy overtook Castroneves for the lead, just as the yellow caution flag light came on for a two-car accident between Buddy Lazier and Laurent Redon. IRL officials' rejected an appeal from Tracy's squad Team Green, upholding Castroneves' second successive Indianapolis 500 victory. He finished no lower than ninth in the next nine races, and battled his teammate De Ferran and Panther Racing's Sam Hornish Jr. for the championship season-long. Before the final round at Texas Motor Speedway Castroneves was 12 points behind Hornish and needed to win the race and for Hornish to finish third or lower to claim the championship. He finished second, 0.010 seconds behind Hornish, ending the season runner-up with 511 points.