If the combustion in vehicles were perfect, only water and CO 2 would be produced.
However, this is not so and a series of other gases and particles are emitted; some of which are harmful and need to be removed.
The main pollutants produced by an internal combustion engine which the law requires to be removed according to EIV standards are:
- Carbon monoxide (CO)
- Nitrogen oxides (NOx)
- Unburned hydrocarbons (HC)
- Particles (especially in diesel engines)