My wife's 2008 prius with 145K miles occasionally won't stay in gear... I've read other posts about this and it seems it fits a scenario that others are having... get in the car, foot on brake, push power button, get the ready light, put car in drive... but when you release the lever, it goes back to neutral. No matter what she does, it won't stay in gear. She can drive the car if she holds the shifter lever in D. Eventually, she will let go of the lever and it will stay in D, sometimes after 1/4 mile and sometimes after an hour. There doesn't seem to be any pattern. Others have noted the shifter lever has to be replaced... Your thoughts please?
No expert here, but like you said "others say shift lever". That is what I have gleaned over the years here on PC for the symptom you are reporting. Supposed to be fairly easy to swap out.
The cause of this has been the deformation of a small piece of plastic that forms a dust shield in the shifter groove. Some have taken the shifter apart and shaved the piece down a bit to restore function. Others have just gotten a used shifter and replaced it. It is DIY, just take the dash apart a bit. Full instructions are here on PC.