2018 RX 350 F-Sport rough idle and occasional stall

ClearTheCode guidance (Lexus · Engine & drivetrain)

Summary: For 2018 RX 350 F-Sport rough idle and occasional stall, work through these steps on your 2016+ vehicle:

1. Confirm the symptom — note when it happens (cold start, highway, after fuel fill, etc.).
2. Scan codes — save all pending/stored DTCs; don't clear until you've recorded them.
3. Check TSBs & recalls — look up your VIN for open campaigns and known fixes.
4. Inspect the obvious — related fuses, connectors, fluid level, and recent repairs.
5. Test the common fix — follow model-specific service procedures; one change at a time.
6. Escalate if needed — burning smell, no brakes, overheating, or stalling in traffic → shop visit.

Owner reported: My 2018 Lexus RX 350 F-Sport has developed a really annoying rough idle lately. It feels like the engine is shaking more than usual when I'm stopped at a light. A couple of times, it's even felt like it was going to stall, though it hasn't completely died yet.

I've noticed it's worse when the engine is warm. No check engine light yet, but I'm worried it might come on soon. Has anyone else experie…

This is educational guidance, not a substitute for hands-on diagnosis.