Lexus IS hybrid engine stalling

That sounds familiar. I had a similar issue with my old Renault Megane, though it was a petrol engine, not a hybrid. The symptoms were almost identical – check engine light and occasional stalling. Did you check the leak detection pump?

Leak detection pump? Interesting. I hadn't considered that. Where was the pump located on your Megane, and what was failing? Trying to see how that might relate to my Lexus. Were there any specific error codes?

On the Megane, the pump was near the fuel tank. The problem was a disconnected hose so the system couldn't build pressure. I couldn't diagnose it myself, so I went to a workshop. It might be best to bring your Lexus to a mechanic and have them run a proper diagnostic on the EVAP system.

Thanks! I took it to my local mechanic, and you were right. It was a leak in the fuel tank ventilation system, caused by a defective activated charcoal filter. New filter installed, system smoke-tested, and the engine is running smoothly again. Total repair cost: 275€. I appreciate the tip about the leak detection – that helped me guide the mechanic!