2021 Toyota Highlander — fuel trims are positive at idle and improve with RPM

I'd want a measurement, not a hunch. Swap the cheap/easy piece first on the 2021 Toyota Highlander and see if the fault moves. That's the branch I'd chase this week. Stop there until you know. Not trying to scare you — just skip the expensive first guess. Video is ugly but it shows the hesitation.

This is usually cheaper to test than to guess. Write temp, speed, and in-gear vs coast when the 2021 Toyota Highlander does it — then decide on parts. If the cheap test changes it, stop and reassess. Do that first. I'd rather pay for diagnosis than a second guess-repair.

Start with the test that can prove you wrong. Write temp, speed, and in-gear vs coast when the 2021 Toyota Highlander does it — then decide on parts. If the cheap test changes it, stop and reassess. This is from a 2021 Toyota Highlander in Orange County. Stop there until you know. Worth doing even if the car feels fine right now. I refuse to clear codes until someone else sees them.

If it were in my driveway, two 2021 Toyota Highlanders can feel identical and have different causes, so measure before you copy someone else's repair. Don't erase codes until someone who can help has seen them. Learned this the expensive way on a previous car. I'd rather be boring and correct. No warning lights, which is why I'm documenting it.

Ask what changed right before it started. Write temp, speed, and in-gear vs coast when the 2021 Toyota Highlander does it — then decide on parts. If the cheap test changes it, stop and reassess. Stop there until you know. Next check is the cheap one I can do in a driveway.

Intermittent stuff lies if you only catch it once. Write temp, speed, and in-gear vs coast when the 2021 Toyota Highlander does it — then decide on parts. That's the branch I'd chase this week. On “fuel trims are positive at idle and,” that was the fork that mattered for me. This is from a 2021 Toyota Highlander in Orange County. Run the total, not the monthly, before you commit. If it repeats twice more I'll book time.

Start with the test that can prove you wrong. If a shop can't duplicate it on the 2021 Toyota Highlander, bring a video plus freeze-frame data, not just a story. That's the branch I'd chase this week. This is from a 2021 Toyota Highlander in Orange County. Had a similar mess a couple years ago and that's what finally sorted it. Your commute and mine probably aren't the same, but the test still applies. Checking again after work.