The Joe Gibbs Racing teams were told to replace the front-end components by officials, and their Toyotas cleared inspection with the new splitters.
The original splitters were taken by NASCAR, which typically re-evaluates parts seized during race weekends on the following Tuesday during a weekly competition meeting at its R&D Center. It was unclear if there would be further penalties from NASCAR.
A NASCAR official said the JGR cars would retain their starting positions.
Asked if he expected any repercussions, car owner Joe Gibbs said: “I don’t think so. I think we’ve just got to change it, that’s all.”
During the NASCAR America prerace show on NBCSN, Marty Snider reported that Adam Stevens, crew chief for Busch, said his car had cleared inspection twice over the past two days without any problems.
Dustin Long contributed to this report.