Last friday I went on a short trip with my S6 (previously I added a can of Liqui Moly injector cleaner). I was pushing it hard like 220-240km/h, but was running low on petrol (like 30kms remaining).
Filled it up with premium petrol and after about 10 kilometers it started missfiring very badly. At least it was 100meters from home.
I was dumb enough to clear the error codes with a simple OBD reader (without saving the stored ones).
Now the car starts fine, but it has really bad missfires. Once the heating of the cats ends it really struggles to keep the idle rpm. (It happend to stall in reverse.)
I left it run a little bit and checked the error codes with vcds, found the below:
Engine I: nothing (just to check number 2)
- 000768 - Random/Multiple Cylinder Misfire Detected - P0300 - 001 -
- 000784 - Cylinder 10 - P0310 - 001 - Misfire Detected
- 000774 - Cylinder 6 - P0306 - 001 - Misfire Detected
- 000773 - Cylinder 5 - P0305 - 001 - Misfire Detected
- 000777 - Cylinder 9 - P0309 - 001 - Misfire Detected
- 000772 - Cylinder 4 - P0304 - 001 - Misfire Detected
There were some misfires in the past, but I changed the ignition coils and the spark plugs too (like 2000kms before).
Here are two videos of the issue:
smoke on idle (It can be seen that only one exhaust is smoking)
One of my friend said maybe it is a collapsed catalytic converter. Can I check it somehow? He told me to pull out the o2 sensors before the cats to see if it helps. Can I do it without dropping the engine?
Thanks in advance.