My 2005 Prius drives fine for the most part, but lately I've had a strange problem. It will drive normally for 5-10 minutes, then it will begin to hiccup when accelerating between 20-30 mph. It almost feels like there are gas bubbles in the fuel line. The car shakes as it accelerates. Other times, the car seems to be confused whether to be in gas, electric, or hybrid mode. Sometimes I will be at a light with a full battery and the gas engine will kick in at a high rpm. Any idea what this could be?
SWAG: dirty throttle plate, caused by chronically overfilling the oil. You've been following the Scheduled Maintenance Guide that came with the car, right?
1. What gasoline brand are you buying? I'm wondering if you have a bad tank of gas. If this persists, then I suggest that you have the iridium spark plugs and the fuel injectors checked. 2. Regarding the engine running while you are at a standstill, this is MG1 spinning the engine to burn off excess traction battery charge and is normal.