Prius not accepting gas

Try reading this page. It talks about the evap filter getting clogged, thus preventing the air from escaping when you fill it.

Why Is My Fuel Tank Not Filling Up and How To Fix It

 

You can follow along in this thread (it is about a Gen 2, but I don't think the Gen 3 and c ORVR systems are a whole lot different, other than lacking the Gen 2 bladder).

One thing you may notice while reading through that thread is that the original poster there had a habitual way of filling up that tends to contribute to the issue, and so even after paying for repairs and being "confident to say the problem is resolved", ended up starting another thread for the same issue about eight months later, to nobody's very great surprise.

 

Just chiming in to let you know that only being able to put 7-8 gallons in a Prius C tank is normal and not part of the issue you’re experiencing. I think when the range is at 0 miles and the tank is “empty” there’s still a gallon or so left as a reserve. My C usually takes about 7.5 gallons to fill it up.

 

Unplug the evap and blow compressed air in the hose to clear

 

There should also be some kind of "anti-siphon" flap in there and it could be causing the problem too.
You are inserting the nozzle in as far as you can, right ?
And it is going in as far as the spring will allow it to, right ??
I agree that the 7 gallons is normal.
My fills usually are closer to 6.

 

Before following any suggestion about your fuel system that has the words "compressed air" in it, please go through pages 5 to 7 here.

 

Pages 5 to 7.....where exactly ??
I agree that mixing compressed air and fuel can be really dangerous.

 

In the PDF file that results from clicking on the blue word "here".

 

Pretty hard to notice that.
At least for my screen colors......and when the word "here" is on a new line by itself.