Have you ever had your oil filter disappear? Where did it go?

The service required light is not for oil changes, just service interval. It comes on roughly every 5K miles IIRC (Canadaian Prius don't have this light). Toyota USA says to rotate tires every 5K, change oil/filter every 10K. It's a fairly popular sentiment here that 10K oil changes are way too long, so that's working out.

Sitting somewhere inconspicuous in your garage?. The 3rd gen oil housing doesn't help: you go through the rigamarole of removing the housing removing the old filter, installing new o-ring on the housing, then spin it back on. Did you miss the step of putting the new filter? Again, I've just about slipped up on this, a couple of times IIRC.

I think you'll be ok, from here on out. 250K on a 3rd gen without head gasket failure is amazing. I'd suspect that diligent previous owner cleaned the EGR and intake. Probably time to do it again. See first two links in my signature (on a phone turn it landscape to see signature).

 

how is the engine running now?

 

Had 290,000 on mine..................

Sold it to some goof for $4500 used about 1 quart every 5000 miles
But it did have a lot of new parts....... I was tired of messing with the junker

 

I think I was just beside the car, working over a drain pan.

there is a conversion to spin-on filter in my signature, has some info.

I use the standard Honda automotive oil filter wrench (I’d describe it as a “socket”). Found it compatible with Toyota and Mazda so far.

 

If the filter had the plastic end caps, they couldn’t get sucked through the center tube. I think maybe the last option is the shop is making it up. Why? I don’t know, some of them lie a lot for no reason.
Could it be they had meant no oil filter as in they didn’t see one on the car?