Every vehicle with a petrol or diesel engine that was permitted to be driven on public roads after 1.1.1976 must undergo compulsory exhaust servicing. Vehicles without a catalyctic converter (with petrol engine) must be checked annually. Vehicles with a catalyctic converter and diesel vehicles must undergo the exhaust check at least every two years. If this exhaust-gas test has not been done, the driver of the respective car risks a penalty (Amount of the fine depends on the date of expiry, 1 month: CHF40, 1-3months: CHF100 and 3-6 months: CHF200). The exhaust service certificate should always be kept in the car in case of police checks.