2023 Subaru Outback — fuel trims are positive at idle and improve with RPM

Agree — and I'd add this: Move a coil or plug on the 2023 Subaru Outback if it's cylinder-specific and see whether the code follows. You'll know quickly if you're on the wrong tree. That's the sequence I'd use. I'd rather be boring and correct. If this is nothing, great. I want that in data.

I hear you, though I'd still want a second check. If a shop can't duplicate it on the 2023 Subaru Outback, bring a video plus freeze-frame data, not just a story. You'll know quickly if you're on the wrong tree. On “fuel trims are positive at idle and,” that was the fork that mattered for me. That's the sequence I'd use. If your situation is the opposite, ignore me. If this is nothing, great. I want that in data.