The air filter box is a paper element type which has to be replaced normally each 30000ml, however more often inspection and change of the element paper is necessary in sites with high dust and degree of dirt. For the carbureted engines, open the engine compartment hood, undo the wing nut at the air filter box assembly, disconnect the crankcase ventilation hose and then extract out the assembly. Remove the filter element then inspect and replace the air filter box mounting gasket if required. A crankcase ventilation filter should be changed with every 20 000 mileage or earlier if the automobile is driven in dusty areas. The air filter box body should be installed with the word FRONT towards the front of the vehicle, and when inserting the new filter element do not forget to tighten the wing nut to the cover and the word TOP should face upwards if any. For fuel injected engines, the hose assembly needs to be undone by loosening the clamps and the inlet tube has to be disconnected by removing the screws fitted in the bracket and the air filter box cover needs to be removed to replace the filter and tubes with caution to be taken not to over tighten the hose clamps. As for diesel engines, the procedure also depends on the model: in the 2.2L and 2.3L models, for instance, one has to open the hood, unscrew the wing nut or, if there is none, use a clip, remove the old filter, check the gasket, put in a new filter, and screw the cover back in place.