Please check fitment notes & description for accurate information. 2002-2004 Audi A6 Quattro 2.7L 2002-2005 Audi Allroad Quattro 2.7L Oxygen Sensor's Location: How do I know the O2 sensor is good or not? Check engine light on A reduction in fuel economy. Your catalytic converter fails unexpectedly Exhaust emissions reach undesirable levels. How to install the oxygen sensor? .
