The IZOD IndyCar Series has served AJ Foyt Racing with a $15,000 penalty fine and hit Mike Conway with a loss of 10pts in the championship after finding the #14 ABC Supply car to have an irregular fuel cell.
The English driver finished in third place in Sunday's race.
IndyCar rules say that the maximum capacity of a fuel cell can be no more than 18.5 US gallons, and technical inspection at Toronto found the component on the #14 to exceed that.
With fuel conservation very much a factor at Toronto, the excess capacity could have had a material effect on the outcome of the race, leading IndyCar to levy a larger penalty than the $5,000 fine imposed on Simon Pagenaud for a similar infringement at Iowa Speedway.
"We felt the discrepancy in the size of the fuel tank was enough that it potentially could have provided a track position advantage and the penalty is reflective of that," explained IndyCar's vice president of technology, Will Phillips.
The team can appeal the penalty, but given that Conway's third place finish from 11th on the grid is unaffected and Conway is not a factor in this season's championship battle, the team will likely just pay the fine and continue to celebrate their podium finish.
Meanwhile, Justin Wilson escaped any penalties for the pit lane accident that occurred during practice on Friday, which saw his car veer out of control and run into Sebastien Bourdais' car parked in the Dragon pit stall. Several Dragon team members suffered minor injuries as a result.
Even though Tony Kanaan was penalised during Sunday's race for knocking a tyre into a pit crew member in Oriol Servia's pit stall, race director Beaux Barfield confirmed that Wilson would not be sanctioned.
"Certainly in the race it would be," said Barfield. "I kicked it around and thought about it, but there were more reasons to not penalise him than there were reasons to penalize him," he said, explaining that it would have been "adding insult to injury" given how dreadful Wilson had already felt about the incident.
Wilson explained afterwards that it had been down to a stuck throttle. "I came down pit lane and the car refused to go into neutral," he said. "So I was stuck in first, I couldn't get neutral, and, on top of that, these carbon brakes don't work when they're cold, so was hard on the brakes and I couldn't stop.