Disconnect the vacuum hose "arrow" (if installed).
Unlock the fastening "4" of the lower part of the air filter (press the rubber elements on the left and right and pull up). The parts (bypass valve with air inlet changeover valve "N335--1") are not installed in all equipment variants. When installing, do not use grease in the attachment points. Remove the air inlet changeover valve connector "N335" (if installed). Carefully remove the air filter housing assembly.
Installation
For the correct operation of the air flow meter "G70" it is important to perform the following operating operations. If the filter element is heavily soiled or wet, dirt particles or moisture may settle on the air flow meter "G70" and introduce an error in the measurement of the air mass. This will lead to a loss of engine power, since the electronics will calculate a smaller amount of injected fuel. It is necessary to always use the original air filter element. When installing the intake hose, it is necessary to use grease (silicone free). If there is a heated air supply hose (only for countries with cold climates) check the reliability of the fixation of the "arrow" of the intake pipe (install according to the marks). Check the drain hose "1" at the bottom of the air filter for contamination and pinching (clean if necessary). Clean the air filter housing (upper and lower parts) from salt, dirt or leaf deposits (vacuum if necessary). Check the air flow meter and air duct (from the filtered air side) for salt, dirt and leaf deposits. Check the intake duct to the filter element for contamination. Connect the air filter bypass valve connector "N₂75" (if installed). Install the lower part of the air filter housing. The drain hose should be directed vertically downwards without kinks.
Connect vacuum hose "3" (if installed) to the air filter bypass valve nipple "N₂75" "1". Carefully install the upper part of the air filter housing without applying too much force.
Check again before tightening the screws that the upper part of the air filter is in the groove of the lower part (to avoid air leakage). After this, screw the upper part of the air filter housing to the lower one. Check the reliability of the air flow meter "G70" air hose fastening. Connect the air flow meter "G70" connector. Installation in the reverse order.