Test Point 21 - Intake System Leak
TEST POINT 21: - Intake system leaksPossible Causes, Elimination, Remarks
Check all connections after the air flow sensor for leaks. Remove the air filter bottom section with air flow sensor and lay aside. Close the hose to the activated carbon canister. Apply special tool 9264/5 to the connection hood and build up a pressure of approx. 0.5 bar (7.25 psi) in the intake system. In the event of leaks, the pressure in the intake system will fall rapidly.
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).