How To Change Audi A4 Oil on 1 B6 Chassis - Blauparts Disclaimer: Refer to the owner's manual and factory manual for Audi oil change instructions. Blauparts recommends having an A.S.E. certified Audi mechanic perform vehicle maintenance. 2003 Audi A4 w/ 1 4 Cylinder 20 Valve Turbocharged Engine - Sedan and Wagon; Install the Audi A4 oil drain plug and washer. Using the 19mm socket 2003 Audi A4 Oil Drain Plug - AutoZone Equip cars, trucks & SUVs with 2003 Audi A4 Oil Drain Plug from AutoZone. Get Yours Today! We have the best products at the right price.