phlenum

I’ve been diagnosing a friends A6 2.8 FSI with roughly 161,000 miles. He experiences loss of power, rough idle and acceleration almost daily when the engine is warm. Since the warm weather has hit us it also occurs very shortly after cold starts. Restarting the engine usually calms down the engine for a short while but the misfires will consistently return.

The engine has consistently been throwing the attached codes. The misfires are only occurring on Bank 1, particularly on cylinder #3 and #1. Swapping the coils from one bank to another made no difference.
Several parts were already replaced to rule out problems including:
- the MAF
- engine breather pipes
- spark plugs
- CPS
- Bank 1 O2 Sensor





I have some ideas on what might cause these codes but I’m looking forward to hearing someone else’s thoughts on this first.