One problem related to engine exhaust system has been reported for the 2005 Audi A4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Audi A4 based on all problems reported for the 2005 A4.
I purchased certified pre owned car from dealership-Audi A4 3. 0 quattro, 2005. 2 days later I could not pass required state inspection due to "check engine" issue-misfire on a 6th cylinder. I brought the car back to dealership a few days later to correct the problem. The problem was corrected temporarily and car passed the inspection-check engine light was reset by dealership. A few months later "check engine" issue came back after scheduled maintenance (at 50,000 miles) was done by authorized dealership. Problem was temporarily corrected 2nd time. In December 2008 after 3rd time "check engine" issue, dealership proposed to replace whole engine in order to resolve this issue, which was done. On February 11, 2009 driving back home from work I've noticed an exhaust gas smell inside the car, car was shaking and "check engine " light was "on"/not steady. I contacted Audi customer service advocates to report the problem and start the case. I brought the car back to dealership for repair 4th time. They performed necessary steps to correct the problem but failed (2 sensors were replaced according to them and "check engine" light still "on"). I was informed that dealership did not replace the whole engine back in December 2008 - they only replaced lower part of the engine knowing that there was a problem with misfire on 6th cylinder (upper part of the engine). After 3 weeks of waiting and constant repairs I am not sure that this problem has been corrected permanently. Facts: car was purchased at 49,000 miles on April 29, 2008. My car has been at dealership for 75-80 days out of 10 months since I purchased it. Total mileage as of February 28, 2009 is 52,450.