After finishing fifth in the Pep Boys Auto 500 at the Atlanta Motor Speedway, Kyle Busch's No. 18 Toyota has failed post-race inspection.
The rear-end housing has been confiscated by NASCAR and will be further inspected at the NASCAR R&D center in Concord, N.C. upon the official return this week.
NASCAR wants to double-check the measurements after the car failed post-race inspection.
Last week, another Toyota team of Brian Vickers failed post-race inspection when it was learned that the team had dipped the sheet metal in acid to make it thinner.
And earlier this year, Joe Gibbs Racing was caught cheating in Michigan when the Nos. 18 and 20 cars in the Nationwide Series were found to have magnets under the gas pedals. It was a move to throw off the horsepower reading during the Dyno tests.
The No. 18 car will be looked over on Monday, and any penalty will be issued thereafter.