The Honda team has been excluded from all results from the Chinese round of the World Touring Car Championship on technical grounds
An investigation by the championship's technical delegate ruled the team's fuel injectors were not compliant with the technical regulations.
Zengo Motorsport has also been excluded due to an identical homologation issue with their fuel injectors.
The Hungarian privateer team was excluded after a later hearing at the Motegi circuit following the decision over the works team a few hours earlier.
It has a significant impact on the championship, even though only half points were awarded for the aborted second race in China.
Polestar Cyan Racing's Thed Bjork now extends his lead in the standings to 3.5 points over the still-absent Tiago Monteiro.
Monteiro's Honda team-mate Norbert Michelisz takes a significant slip back to fourth in the championship, 32.5 points behind the Volvo of Bjork, and also falls behind the second-best placed of Volvo's drivers, Nicky Catsburg.
Honda's lead in the manufacturers' championship has also been reversed.
Volvo initially moved 11 points ahead with three race weekends remaining in Japan, Macau and Qatar, as the works Honda's team's exclusion meant Zengo briefly picked up the manufacturer points in its place.
But with no Hondas at all now registering any points in China, Volvo's lead in the manufacturers' championship is 64.5 points.
The injectors of all the Honda Civic WTCCs were marked for further investigation during Friday's scrutineering session in China, with the results of the race marked as provisional.
Following a meeting in Geneva ahead of this weekend's races in Japan, the FIA technical department has ruled that the three cars of the factory Honda Racing Team JAS squad had not complied with the homologation procedure.
Honda has accepted the decision, and put the transgression down to a difference in interpretation of the FIA homologation procedure.
"While we accept this unfortunate decision of the race stewards, we wish to stress that we have acted in good faith at all times," said Ryuichi Furukawa of Honda's engine research and development team.
"Unfortunately, the way we have interpreted the homologation process is different to that of the FIA.
"We are incredibly disappointed with this judgement as the fight for both the drivers' and manufacturers' championships will now be extremely difficult.
"However, we will continue to push as hard as we possibly can at the final three rounds of the season to achieve our aim of winning the world championship.
"We would like to take this opportunity to apologise to our fans and everybody else who has supported our WTCC efforts this year."
The exclusion is the second for the Japanese manufacturer in two years, with Honda's cars also excluded from Marrakesh last season.
That time the cars' flat floor was found to not be compliant.
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