2021 Audi A6 — fuel trims are positive at idle and improve with RPM

I'd want a measurement, not a hunch. Two 2021 Audi A6s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. Post the numbers (or the code) and people can get more specific. This is me being the wet blanket on purpose.

Log the conditions before you spend. Two 2021 Audi A6s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. On “fuel trims are positive at idle and,” that was the fork that mattered for me. If it doesn't change the out-the-door or the repair estimate, it's noise. Cold start is when I can actually reproduce it.

Start with the test that can prove you wrong. If a shop can't duplicate it on the 2021 Audi A6, bring a video plus freeze-frame data, not just a story. If the cheap test changes it, stop and reassess. Happy to compare notes if your setup is different. Worth doing even if the car feels fine right now. I'm in no rush to be a hero on it.