RX350 Cylinder 3 misfire
 

I own a 2008 RX350. It has been a great vehicle, and my wife says she just feels safe in it. About 10 days ago, she said it was idling rough and had the check engine light on. I plugged in my code reader to find a #3 cylinder misfire. I did a complete service on it at 122,000. miles, including OEM plugs, coils, PCV, belts hoses fluids, transmission filter, gasket and fluid. With only 4500 miles since the service, I just couldn't believe that a plug and or coil could be at fault. However, after swapping #1 coil with #3, the code switched to #1 cylinder. I replaced the coil and the spark plug. Even the plug showed signs of wear. (Probably because of the misfiring) The car runs great again. Lesson: New components fail! Just because some parts were replaced recently, does not mean it cannot fail!