A8: Emission Control Systems Diagnosis and Repair Air Injection System Catalytic Converter (2004+) Catalytic Converter Operation Catalytic Converter Temperature Test Check Exhaust Gas Temp EGT Dual Cell O2 Sensor Voltage Check EGR System Tests Evaporative Emission Control System Evaporative Emission Control System Test Exhaust Gas Recirculation, EGR Exhaust Gas Temperature Sensors Positive Crankcase Ventilation (PCV) Positive Crankcase Ventilation System Tests Secondary Air Injection
