Prius topped off gas by the gas attendant...

I don't top mine off one bit. Mainly because I wouldn't dare splash any fuel on my paint

Mike

 

I parked my Prius with no fuel in the tank on a Friday. The display said 0 miles till empty. On Monday morning I was going to add a few gallons from the gas can in the garage just to get to work then full up. I didn't know that my spouse had used it on Sunday and filled it up with gas. When Monday came, I began adding fuel thinking it was still empty. I managed to get almost 2 gallons in the tank when it began to run out the fill neck. It was full to the very top. That was about 2 months ago. No check engine light. No rough running.

 

roger, pump your own fuel. then there is not anything to worry about.

 

Had no idea about the evap system damage by topping off. 2013 Lexus CT200h (equivalent to Gen III Prius). Been routinely topping off, almost every time, all the way to the top of the filler neck. I did this because it gets me 500 mile range, almost always and I usually run the tank really low.

Bad idea, I find out. But it all worked out well:

1) got check engine light
2) borrowed OBD-2 reader and got 3 codes, including P0441 (sometimes a gas cap leak)
3) bought a Scan-Guage-II and installed (fantastic product!)--same P0441, but not the other two codes with the ScanGuage
4) cleaned gas cap really well and replaced O-ring--no luck. CEL came on repeatedly.
5) After much research, decided I needed Tech-Stream software to fully diagnose. Don't have a Windows computer, didn't want to mess with Linux systems and software, etc, etc. Gave up and went to dealer.
6) They were able to diagnose bad Purge Solenoid ! (YEY, Charcoal canister ok!)
7) I'll replace valve myself.
8) Found out with reading today about that valve and the Evap / Emissions system, I likely killed this valve (just under 100k miles) with overfilling tank, routinely. Won't do that any more.

Now I learned about not overfilling (thanks community!) and am hopeful I haven't really damaged my charcoal canister too, too much. No need for me to be filling like that. New habit formed.

 

^ Cheap lesson.

If you're not into the Linux, you should still consider getting a beater WINTEL box, putting it in "airplane mode" and using it for Techstream only....especially if you're gonna keep the car for a few more years.

You can get this done for about the same price as a Yota dealership would charge for a diagnostics fee.