NASCAR has stripped Joe Gibbs Racing drivers Tony Stewart and Joey Logano of 150 points each and their crew chiefs were suspended indefinitely Wednesday for cheating during Saturday's Nationwide Series race.

Crew chiefs Jason Ratcliff and Dave Rogers were also fined $50,000 each, and five other crew members were suspended indefinitely.

After Stewart finished third in Saturday's race at Michigan International Speedway in the No. 20 car and Joey Logano was seventh in the No. 18, inspectors found magnets under the gas pedals of both cars in attempt to mask the cars' true horsepower.

Gibbs' No. 18 and No. 20 Toyotas have dominated this season, combining to win 14 of 25 Nationwide races. NASCAR last month ordered all Toyota teams to cut about 15 horsepower in their motors.