The largest offender in air is water vapor. When the tires cool down, the vapor condenses into water and the pressure decreases. However as the tires heat up, the water vaporizes again and the pressure rises above the value predicted by Gay-Lussac's law.

Nitrogen has had not only oxygen but water vapor removed from it.

The true smart man is the one who appears to be dumb in front of dumb man who appears to be smart.