Bought 2007 S6 in April of 2011.
I wanted to list out the issues I have had with my car since there seems to a common theme with misfires.
Multiple misfires - Codes: Bank 0/1 running lean, misfire on multiple cylinders
Causes
- bad ignition coil on #4
- bad fuel injector on #8
- carbon clean was performed
Cranked overflow tank
Cranked air breather tube
Inner CV boot replaced on FR
Do not use BP gas, only use Shell. BP fuel causes more misfires and rough running plus they had bad batch gas where I live where is destroyed peoples CATs.
Multiple oils leaks which has caused me to pull the engine for a rebuild. The leak is between the engine halves to the right of the crank seal. Pulling the engine next month and will document.