Following the penalty issued to Joe Gibbs Racing’s No. 20 Sprint Cup Series team  and driver Matt Kenseth, Toyota Racing Development held a parts review. As a result, three engines belonging to Michael Waltrip Racing’s No. 15 Sprint Cup team and driver Clint Bowyer as a precautionary tool.
One of the engines was going to be his primary engine in the Toyota Owners 400 at Richmond International Raceway. The other two were his primary and backup engines for the Aaron’s 499 at Talladega Superspeedway.
David Wilson, of TRD, said:
We took every connecting rod in our inventory and removed anything that was too close for comfort.
The review revealed that one connecting rod in each of the three recalled engines was too close to NASCAR thresholds for comfort.
According to reports, the connecting rod in Kenseth’s race-winning Toyota  was outside of the tolerances the manufacturer allows on weight before it was shipped. TRD employees missed it, despite the fact that the connecting rod came with paperwork that clearly stated its weight.