translate English to French: The text includes a definition of tampering, the frequency of tampering with emissions control components, the effect of individual component tampering on vehicle emissions, the net effect of in-use fleet tampering on airshed emissions, and enforcement methods for reducing tampering in on-road vehicles.
Il dÃ©finit cette pratique et en examine la frÃ©quence et les rÃ©percussions sur le dÃ©gagement de polluants par les vÃ©hicules non conformes et sur la qualitÃ© de l'air Ã l'Ã©chelle du pays. Il recommande aussi des mÃ©thodes de contrÃ´le visant Ã limiter cette pratique.