In desperate need of help

That dealership sounds sketchy. $160 for a diagnostic scan and $3000 to replace a fuel pump? The whole process for the scan takes about 5 minutes. I have no idea if that $3000 is reasonable, but it sounds much too high for any kind of fluid pump installation, at least in general. Rock auto has an ~$300 part which looks like a combined tank and pump. That is not an OEM part though, and who knows how much labor is required to swap one.

Surely there must be an independent mechanic somewhere in your vicinity who works on this model car. Search these forums, or start with the names in this thread and if they are out of range, perhaps they can suggest somebody:

Los Angeles Mechanic | PriusChat

 

Fuel pump may be expensive because of the bladder fuel tank; might require changing the whole tank. Gen 3 has a non-bladded tank and the pump can be replaced on its own.

It's true, there's a long list of things that can cause reduced engine power. That's always been true of engines. It doesn't really pay to try to just replace all those named parts and see what happens. And it's important to remember that, say, a mass airflow reading doesn't just depend on the MAF sensor ... it depends on the wiring that goes to the sensor ... it depends on the tube where the sensor's mounted being airtight ... and so on.

Really, with a situation like this, one has to look up how to diagnose a gasoline engine with reduced power, and do that. If there are specific codes from the ECM, they can help point you in a productive direction, but they aren't an answer key in themselves.

 

yes, a gen 2 requires replacement of the entire fuel tank/fuel pump as an assembly. I'm impressed that you went and made that purchase and did that installation on your own. That's a lot of work, including all the other various items replaced.

The 'runs about ten seconds' is more likely the car spinning the engine trying to start it, not actually the engine running.

An engine needs three things...air, fuel and properly timed ignition. One thing I've found that works well to verify a bad fuel source is to spray some starter fluid into the throttle body as someone else attempts to start the car. What's convenient about a Prius is you can press the power button, and then walk to the front of the car to be the sprayer also since it takes several seconds before the engine starts trying to spin for ignition. If you can keep it running using starter fluid, but the car dies without it, then the fuel system is your likely culprit. If the car won't run, even with starter fluid, then it's more likely something else is bad, like no spark or no airflow into the cylinders.

 

Do you have gas in the car? Prius cars that stall like that usually run out of gas

 

I had that happen after cleaning the throttle body and MAF...some dirt got on the MAF after cleaning the air filter box. Make sure the air filter is not clogged and clean the MAF for starters. Clogged fuel injectors are more likely than a bad fuel pump; I had fuel trim readings of +3.91% before running fuel additive injector cleaners for 2 tankfuls...now down to +0.5%. These tiny motors are finicky about these things.

Have a look at the spark plugs to see how its running.

Go for the simple and less expensive things first before replacing major parts.

 

If you want to tow it to a shop that sees a lot of Prius cars, you can try the Hybrid Pit in Buena Park. Not too far from you and they would be able to sort the problem out for you