I've read a few posts related to this. I just purchased a used 2006 package 3 with 66500 miles on it. Drove it to work today and the car started sputtering/shuddering when i was accelerating onto the highway. The check engine line came on so I took it to the dealership. Turns out it was a bad sensor. When they fixed the bad sensor, the mechanic told me that its normal to feel a slight studdering when the gas engine kicks in or off which seems to be confirmed by other members here. This afternoon, I was idling at a light and I felt the sputtering/studdering again but it was much more pronounced. Thank goodness no check engine light came on. Any cause for concern? I don't think there is much the dealer can do if no service lights or warnings pop up.
What sensor was replaced? What DTC (diagnostic trouble code) was logged by your car? Since your area currently has heavy rain, perhaps your engine has a misfire due to water getting into the spark plug wells. Eventually that will trigger a DTC and the check engine light will appear.
What the OP describes isn't normal. The start/stop shudder is pretty mild, often unnoticed, unless the engine is cold. Tom
I'll have to look at the paperwork for the codes. Is there any long term damage if water gets into the spark plug wells? Are any other SOCAL Prius drivers experiencing this?
I've seen at least one other poster from your area with a similar misfire problem yesterday. The only long term damage is that it is necessary to replace the spark igniters and spark plugs.
