One problem related to o2 sensor has been reported for the 2003 Volkswagen Passat. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Volkswagen Passat based on all problems reported for the 2003 Passat.
Coils failing randomly and causing the car to shake violently and lose power on highway. Potential damage to be caused to other areas of the car because of this. Ie oxygen sensor etc.