A4 Diesel Reset Drift Fix: Real Owner Guidance

Had a similar issue with an A6 2.0 TDI from 2006. The symptoms matched exactly, rough idle and check engine light, particularly noticeable when cold. The fuel injection system needed attention after diagnostic tests revealed drift compensation values were outside normal parameters. The fix required a complete system reset and recalibration of the airflow sensors, followed by compensation adjustment of the injection valves. One faulty injector was causing incorrect fuel delivery, throwing off the entire drift compensation. This was indeed a serious issue that needed immediate attention. Leaving it unfixed risked damaging the engine due to improper fuel distribution. The repair involved removing and testing all injectors, replacing the defective one, and performing a full fuel injection system calibration. The critical part was ensuring proper diagnostic equipment was used, many shops lack the specific tools needed for proper drift compensation reset on these engines. Best to confirm the shop has experience with VAG diesel injection systems before proceeding. After repair, the engine returned to smooth operation with proper idle. Regular maintenance since then has kept the fuel injection system working correctly without further drift compensation issues.

Thanks for sharing that experience. My A4 has shown very similar symptoms and hearing about successful fixes gives me hope. Did it end up being just the one injector in your case? The mechanic mentioned a performance tuning and system reset might be required along with new parts. Could you recall the total repair cost? I want to budget properly since these injection system repairs can vary widely. Also wondering if any other issues popped up in the months after the repair was done?

Thanks for asking about the follow-up. After seeing the mechanic, the reset quantity drift compensation issue was fully resolved. It was indeed just one faulty injector causing all the trouble in my case, the onboard diagnostics confirmed this after thorough testing. The total repair came to 515 Euro for fixing the defective injection valve. The price included the necessary system reset and performance adjustments to get everything running smoothly again. The mechanic also checked all airflow sensors during the process to ensure the engine management system would work correctly after the fix. Since the repair six months ago, the engine has been running perfectly with no drift compensation warnings or rough idle issues. Regular diagnostic scans show all injection parameters staying within normal ranges. The investment was worth it to prevent more serious engine problems down the line. For peace of mind, I did three follow-up scans over the first few months after repair, all confirmed the system was functioning correctly with no additional issues appearing. The stable idle and smooth performance have remained consistent since the fix.

Really appreciate the detailed feedback. Finally took my A4 to a different shop that specializes in fuel injection systems. They found two faulty injectors causing the drift compensation issues, plus a worn sensor that needed replacement. Total bill hit 780 Euro but the onboard diagnostics now show everything running within spec. The repair process took longer than expected, about 3 days total. They did a complete system reset and performance tuning after replacing the parts. Fuel economy has actually improved since the fix, and the rough idle is completely gone. Had them do a follow-up scan after a week of driving just to be sure. Everything checked out perfect with no error codes. The engine runs smoother than it has in months, especially during cold starts. Was definitely worth finding a shop that knew these systems well.