NASCAR takes the winning auto, the runner-up and any other cars it determines - either by "random" or by choice - to its research center in North Carolina for additional inspection, a process that often takes a few hours. The infraction was discovered in postrace inspection at the NASCAR Research & Development Center in Concord, North Carolina.
Harvick has been in NASCAR's finale three of the last four years.
Harvick's crew chief, Rodney Childers, and vehicle chief, Robert Smith, were suspended for the final two races of the season.
The stripping of all win bonuses, plus the championship point reduction, means that Harvick is now just three points above the cutline to advance into the Championship Race.
"We need to change the culture to where we don't have to play this cat and mouse game with the teams", Miller said.
"We will try to do that in pre-inspection, and then I think that we have enough eyes to know if a spoiler comes off a auto, then we go on high alert on that one", Miller said.
The issue was with a spoiler that had been modified to give Harvick an aerodynamic advantage as he dominated and won for a Cup Series-high eighth time this season. The team has not made any members available for comment, and Harvick is not scheduled to speak to the media at Phoenix, where he is a nine-time victor.
"As black and white as it gets", Miller said in a Wednesday night conference call.
Harvick's team has the ability to appeal the penalties issued after the Texas race, but the team has announced it will not exercise that option. Later in the same event, Bowyer was penalized for a crew member being over the pit road wall too early.
Harvick is not the only driver to get an L1 penalty. Although this isn't the proper time for Martin Truex Jr. or Aric Almirola to get Logano back, if either one has his eligibility ended or becomes locked into the Championship 4, don't be surprised when cameras cut to Logano hitting the wall after one of those drivers, or even a new Logano hater, hits him to end his race. All three were expected to race for the championship, and none is qualified for Homestead yet with one race remaining.
NASCAR later allowed Miller to answer questions about Harvick's penalty because of the magnitude of the situation.
As far as other penalties go, Texas runner-up finisher Ryan Blaney and fourth-place finisher Erik Jones were each docked 20 points for postrace violations in addition to seeing their crew chiefs suspended for the final two contests. Nick DeFazio will be the interim vehicle chief. Jones crew chief Chris Gayle was fined $50,000 and auto chief Jason Overstreet was suspended the next two races.