Highlander hybrid idle air control issue

Sounds frustrating! I had a similar issue with my old Volvo S60. Check engine light, stalling at idle... the whole nine yards. For me, it was the throttle body that was gunked up. That can cause weird idle issues. Have you checked the intake for excessive carbon buildup or debris? A good cleaning might be all it needs. How many kilometers are on it?

Thanks for the tip! I didn't think about the throttle body specifically. It's got about 20615 km on it. Where should I be looking for the buildup? And what's the best way to clean it without messing anything up?

Okay, that's not a ton of kilometers, but buildup can still happen, especially with hybrids doing lots of stop-start driving. The throttle body is right after the air intake, before the intake manifold. You'll probably see black, oily gunk. I wouldn't go spraying a bunch of cleaner in there unless you know what you are doing. You don't want any cleaner getting into the engine and causing damage. I'd honestly recommend taking it to a trusted mechanic. They can diagnose it properly and clean it without risking damage. I ended up paying around 425€ for the repair.

That sounds like the way to go. I was hoping to avoid the mechanic, but I don't want to risk making things worse. Thanks a lot for the advice! I’ll take it in and see what they say.