Updated

The Associated Press is reporting that the engine in Matt Kenseth’s No. 20 Joe Gibbs Racing Toyota failed inspection following Kenseth’s victory in Sunday's STP 400 at Kansas Speedway.

According to the AP, one of the connecting rods in Kenseth’s engine was too light.

When contacted by SPEED.com, NASCAR declined comment on the report.

Historically, NASCAR reacts harshly to engine irregularities.

In 2009, Carl Long was fined $200,000 for having an engine that was 0.17 cubic inches oversized during practice for the Sprint Showdown at Charlotte Motor Speedway. The fine, which Long still hasn’t paid, effectively ended his Sprint Cup driving career. Long still works in the NASCAR Nationwide Series, where he has made one start so far this year.

This is the second major rules infraction case this year.

Penske Racing was busted at Texas Motor Speedway two weeks ago and has a May 1 appeal date. Seven Penske team members — the team manager and the crew chief, car chief and engineer for both the No. 2 and 22 cars — were suspended six weeks each. The suspensions are pending the completion of the appeal process.

Tom Jensen is the Editor in Chief of SPEED.com, Senior NASCAR Editor at RACER and a contributing Editor for TruckSeries.com. You can follow him online at twitter.com/tomjensen100.