Can anyone help solving issues? Audi A6 C7 3.0 TFSI Prestige

Seeking Advice
1

Hello guys, I’m having some issues with my Audi A6 C7 3.0 TFSI 310hp. Recently, I’ve had misfires on cylinders 4 & 3. I changed 6 coil packs and spark plugs, but the issue stayed. So, I sent the car to a mechanic to get 2 injectors changed. The issues were fixed, and the car was working perfectly… for 2 days. Now I’ve got these codes:

  • P030400: Cyl. 4, Misfire Detected
  • P030200: Cyl. 2, Misfire Detected
  • P030000: Random/Multiple Cylinder, Misfire Detected
  • P020400: Cylinder 4 - Injector Circuit
  • P020200: Cylinder 2 - Injector Circuit
  • P215100: Fuel Injector Group ‘B’ Supply Voltage Circuit High
  • P130A00: Hide Cylinder
  • Comfort Central Control Unit issues.

I’ve tried looking for solutions online, but it’s not helpful. I’ve got a rough idle, hard to accelerate, and a shaky engine. I took out the ECU, drained some water, dried it, and cleaned it, but the issue is still there. After clearing codes while the engine is running, it runs smoothly for a moment, then the issues come back. I have 260k km on it. Has anyone experienced similar issues? What can be potential solutions? Could the cats be clogged and causing back pressure that messes with voltage? Is it a faulty relay? Please help.

2

Sounds frustrating! It could be a few things. I’d check the wiring and connectors to the injectors. Sometimes they can get corroded or damaged.

3

Sage said:
Sounds frustrating! It could be a few things. I’d check the wiring and connectors to the injectors. Sometimes they can get corroded or damaged.

Thanks! I’ll take a closer look at those. I did notice some wear on the connectors.

4

Given the mileage, clogged cats could definitely be a possibility. If they’re restricting airflow, it could cause those misfires.

5

QuattroGenius said:
Given the mileage, clogged cats could definitely be a possibility. If they’re restricting airflow, it could cause those misfires.

That makes sense. I’ll have to check that out too. I appreciate the advice!

6

Have you checked for vacuum leaks? They can sometimes cause rough idle and misfires.

7

Haru said:
Have you checked for vacuum leaks? They can sometimes cause rough idle and misfires.

Not yet, but I’ll definitely add that to my list. Thanks for the tip!

8

It might also help to reset the ECU after drying it out to see if that clears up any lingering issues.

9

Lin said:
It might also help to reset the ECU after drying it out to see if that clears up any lingering issues.

Good idea! I’ll try that as well. Hoping to get this sorted soon.