Taking much longer than usual to enter Stage 4???

I drove the Prius twice today, and each time when I noticed it was in hybrid stage 3 (engine continuing to run during low speed glides) I stopped and let it idle until it entered stage 4.

The first time I was stopped at a set of lights, and though I didn't time it, it seemed to idle for much longer than usual (about 20 seconds) before it finally cut out. I thought it was probably just a one off anomaly, but when I made the return journey home and tried it again, and this time it idled for 17 seconds before cutting out. Normally it only takes 7 to 10 seconds. I wonder if this is a bad omen, like an oxygen sensor or something is just about to go?

 

Yeah today was very warm here, I wonder if that has anything to do with it. Also my Prius is slightly overdue for an oil change, but I checked the oil and all the fluids and everything seems fine. There doesn't seem to be anything wrong with the performance, apart from just this unusually long idle to stage 4.

I'll have to try it again tomorrow and report back.

 

Ok, good to see that I'm not alone.

Anyway here's the update. This only happened the two times that I mentioned in the opening post. It was two consecutive times in the one evening, which made me wonder if something was starting to go bad.

However since then it hasn't happened again. I drove it three times yesterday, and each time I let it idle to stage4, and it only took about 7 seconds. Then I drove it twice today, and again both times it was well behaved. So happily everything seems totally back to normal.