Why did Highlander waste oil after cleaning the accelerator?

Yes, it is possible. In the past, your car's computer has adapted to your driving style and has been adjusted to the best condition. This time, due to the matching after cleaning the throttle, the throttle memory was cleared and returned to the factory default state. It doesn't matter. After driving for a while, the computer will automatically re-match your driving style, and the fuel consumption will naturally come down.