2.0L turbo charged engines may develop a hesitation on acceleration and/or illumination of the Check Engine Light due to a failed high pressure fuel pump or a worn camshaft follower or camshaft. Our technicians tell us that whenever the high pressure fuel pump is replaced the camshaft and the follower should be checked for wear. The camshaft lobe pushes on the follower to operate the high pressure fuel pump. Frequent oil changes and use of synthetic oil may help with this wear issue.Google+
Car Problem Reports
Audi A4 Check Engine Light and/or Hesitation Due to Failed High Pressure Fuel Pump
Audi A4 Problem
Engine Affected: 2.0L 4 Cylinder Turbo
Average Mileage: 93,295 mi (80,000 mi - 106,590 mi)
Visitor, 2006 Audi A4, 2.0L 4 Cylinder Turbo, 106,590 mi
Replaced under warranty by Audi. The dealer told me this is a known problem and Audi has extended the warranty on this part for 110,000 miles.