Fuel Delivery and Air Induction: Testing and Inspection

Check all connections downstream of the air flow sensor for leaks. Remove upper air cleaner section. Attach Special Tool 9264/4 to the air mass sensor and build up a positive pressure of approx. 0.5 bar in the intake system. Leaks will cause the pressure in the intake system to drop quickly.

NOTE: Fault flashing code 1_23 (oxygen regulator at stop) appears in cars with oxygen regulation and very large leaks in the intake system (e.g. intake pipe gasket).