Home >> Audi >> 2003 >> RS 6 >> Repair and Diagnosis >> Engine Mechanical >> Blowers, Superchargers & Turbochargers >> Exhaust System, Emission Controls - 4.2L V8 5V BITURBO - BCY >> Exhaust System, Emission Controls >> Secondary air system, overview >> Combination valve for secondary air system, checking function, checking for leaks >> Requirements for test: