Vehicle with sensing means for determining the gas composition of the air and with a reducing system for one gas

The vehicle comprises a measuring probe arrangement (1) for acquiring the gas composition of air for the engine and/or air conditioning/ventilating unit fed to the arrangement. Preferred Features: The measuring probe arrangement has a sensor unit (2, 3) for generating a measuring value indicative of the ozone concentration in the ambient air. The vehicle comprises an ozone reducing unit for converting ozone into bi-atomic oxygen molecules. The sensor unit (2) is arranged in an engine suction air channel. The ozone reducing unit comprises a catalyst surface located in the engine chamber.