AUDI: POOR PERFORMANCE BECAUSE OF LEAK IN VACUUM SYSTEM. VACUUM LEVEL BECOMES TOO LOW BECAUSE OF DAMAGED, TORN OR KINKED VACUUM HOSES; LOOSE VACUUM HOSE CONNECTIONS. VACUUM LEAKS SLIGHTLY DECREASE ENGINE PERFORMANCE BECAUSE OF THE LACK OF ADDITIONAL AIR ENTERING THE ENGINE AT HIGH RPM. THIS CONDITION DOE NOT CAUSE STALLING. *PE