P0172

SAE VAG Description
P0172 16556 System Too Rich Bank 1

Exhaust System
- Exhaust manifold, front exhaust pipe with Three Way Catalytic Converter (TWC) and attachments. Three Way Catalytic Converter (TWC), Checking
- Exhaust system components, removing and installing. Service and Repair
- Mufflers with mounts. Service and Repair
- Three Way Catalytic Converter (TWC), checking. Three Way Catalytic Converter (TWC), Checking

Fuel Injectors
- Fuel injectors, checking. Fuel Injectors, Checking
- Fuel rail with fuel injectors disassembling and assembling.

Fuel Supply System
- Fuel injectors, checking. Fuel Injectors, Checking
- Fuel pressure regulator and residual pressure checking. Fuel Pressure, Regulator and Residual Fuel Pressure, Checking
- Fuel Pump (FP) and sender for fuel gauge, component overview. Locations
- Fuel pump checking. Fuel Pump, Checking
- Fuel pump, removing and installing. Service and Repair
- Fuel rail with fuel injectors disassembling and assembling.
- Fuel tank with attachments, component overview. Locations
- Safety precautions when working on fuel supply. Service Precautions

N80 - EVAP Canister Purge Regulator Valve
- Evaporative Emission (EVAP) canister purge regulator valve checking. EVAP Canister Purge Regulator Valve, Checking

Oxygen Sensors
- Exhaust manifold, front exhaust pipe with Three Way Catalytic Converter (TWC) and attachments. Three Way Catalytic Converter (TWC), Checking
- Exhaust system components, removing and installing. Service and Repair
- Oxygen Sensor (O2S) and oxygen sensor control before Three Way Catalytic Converter (TWC) checking. Oxygen Sensor and O2S Control Before Catalyst, Checking
- Oxygen Sensor (O2S) heater for oxygen sensors behind Three Way Catalytic (TWC) checking. Oxygen Sensor Heater Behind Catalyst

Vacuum system
- Vacuum line layout. Diagrams

Note: Check exhaust system for leaks. Check vacuum lines for leaks.