I can feel the vibration in park, neutral, and drive while stationary. Much worse in neutral and park than it is in drive. When I’m in the 1900-3000 rev range, vibration has the same pattern no matter what gear I’m in. Builds up as I get to 2500 and then starts dying down as I approach 3000. From 1000-1900, it’s just a constant low vibration.
Today I also found that on a cold start, it’s especially bad when reversing. Feels like the car wants to lurch forward every half second. No issues reversing when it’s at operating temperature. No issues with the transmission shifting and no codes there either.
VCDS showed short term fuel trim while idling was mostly in the +0-5% range, but would randomly spike between +10-20% on both banks for a few seconds before going back down. Long term fuel trim was 2.7%. I’m also getting a code for random/multiple misfire and misfires across all cylinders. Just to be sure, I tested all the ignition coils (which I never replaced) in a friend’s 4.2 A6 and it ran perfectly fine. Gonna try getting it in for a vacuum line smoke test.
Also, is it normal that the engine won’t go past 6000 RPM while driving once the flaps have been locked? I did get a flashing CEL once I approached that range. I don’t recall anything mentioning that when I was reading up about locking the flaps, so maybe it’s related to whatever the issue here is?
Thanks for all your input so far, I appreciate it!