Walker 245-1221 Mass Air Flow Sensor

Walker Mass Air Flow Assembly 245-1221

Walker Mass Air Flow Assembly 245-1221 is a direct-fit engine management sensor assembly for select Audi and Volkswagen applications. It is built with a housing included and a 5-terminal female connector layout for service replacement on vehicles that use this configuration.

Walker Products has supplied fuel system and engine sensor components since 1946, with manufacturing and engineering support focused on OE-level fit and specification control. The Walker Mass Air Flow Assembly line is aimed at accurate vehicle application coverage and dependable replacement for import air metering systems.

Key Features

• Mass air flow sensor assembly for emission control and engine management service
• Housing included for a complete replacement assembly
• 5-terminal female connector
• Built for select Audi A3 Quattro, TT Quattro, and Volkswagen Eos, R32, Touareg, and Passat applications
• Cross-reference: Bosch 0280218073
• Part number: 245-1221

Detailed Description

Walker 245-1221 is a mass air flow sensor assembly used to measure incoming air for proper fuel delivery and drivability control. This part is listed for 2002-2009 Volkswagen Passat, 2003-2004 and 2008 Volkswagen R32, 2004-2006 and 2007 Volkswagen Touareg, 2007-2008 Volkswagen Eos, 2004-2009 Audi TT Quattro, and 2006-2009 Audi A3 Quattro. It also cross-references Standard Ignition MAS0340 for the same application. If you are searching for a mass air flow sensor for 2006-2009 Audi A3 Quattro or a replacement mass air flow assembly for 2004-2006 Volkswagen Touareg, this part number should be verified against the original connector and housing style before installation.

Common Issues This Part May Address

• Rough idle caused by inaccurate airflow readings
• Hesitation or poor throttle response during acceleration
• Check engine light related to air metering or sensor performance
• Fuel trim concerns from incorrect air/fuel calculation
• Driveability problems on Audi and Volkswagen models with a failing MAF assembly

Installation Notes and Tips

Confirm connector style, terminal count, and housing configuration before installation. This assembly uses a female connector and does not include mounting hardware. Inspect the intake tract, air filter housing, and wiring connector for contamination or damage before replacing the sensor. After installation, clear diagnostic trouble codes and verify idle quality and airflow readings with a scan tool.

Quality Assurance

Walker Products manufactures engine sensor and fuel system components to meet or exceed OEM standards and specifications. The company is ISO 9001 and IATF 16949 certified, with product management and engineering support used to maintain application accuracy and technical documentation.