Lexus LS Fuel Injector Issue

The symptoms strongly suggest a fuel injector issue. A defective injector can cause the engine to run rich. Fuel injector cleaner is often ineffective for severe cases. Have you checked the oxygen sensors or considered a faulty mass airflow sensor? What codes are being reported by the check engine light?

I haven't checked the oxygen sensors or the mass airflow sensor, as I'm not sure how. I also lack the equipment to read the error codes. Can you elaborate on how to check these components? Is it something a novice can undertake, or should I see a professional?

Given you lack diagnostic tools, I recommend taking your Lexus to a qualified mechanic. Checking the oxygen sensors and MAF sensor requires specialized tools and knowledge. Driving it in its current condition could damage the catalytic converter. A defective fuel injector is the most probable cause, but a proper diagnosis is necessary. Replacing the injector should solve the problem and cost around 515€.

I took your suggestion and brought the car to a mechanic. They confirmed a faulty fuel injector. They replaced it, and the car now runs like new. The total repair cost was 515€, as you predicted. I am grateful for your guidance; you saved me time and potential further damage.