One Friday evening, I decided to flush the cooling system on my Prius C 2012. I mistakenly cut the wrong hose. I should have realized that it was the wrong hose because no coolant came out. However, I still connected my water hose and forced water in expecting water to come out through the radiator, but that didn’t happen. I then decided to reconnect the hose and replaced the clean coolant. When I started the car, the engine started making some shaking sounds but thought nothing of it. The next day, the car showed the “check hybrid system light stop immediately” issue and I got really scared. I called the nearby Toyota Service and was advised to tow it there a day early (the car was due for the next oil change service the next day). I explained to them what I did hoping that they would be able to help fix my error. I also mentioned to them that I don’t plan to spend so much on this car and that I would want to know the quotation well in advance so I could make a decision whether to fix the car or buy another. It took them over 24 hours before they got to my car and when they did, they called and advised that they will need to do a tune-up, replace sparks plugs, Mass Air Flow sensor, and air filter. Parts and services were over 1k and that the car would be ready in 48 hours. I thought the cost and time frame were reasonable and thus assented. When I called to check if the car was ready, they reported that the car would not stay running. They did further diagnosis and found that the fuel sender needed to be replaced. This was going to cost me another 1k. I grudgingly agreed for the service. On Friday when I called to arrange, to get the car after work, I was told that while the tech was installing the fuel sender, they found out that the fuel tank was severely contaminated and therefore the fuel tank needed to be replaced as well. That would cost me over 1K. I got really mad and demanded my car back. I decided that it was time for me to learn more about my car and stop depending on others. So, I took a day off to work to figure out the damage I did when I forced the water through the intake hose. I followed the house all the way to the canister. I took it out and found it damp. Water had dissolved carbon-like material. The canister had a connection to the fuel tank. I tried taking the fuel tank down with no success. I then took the fuel pump assembly to reach the fuel tank where I discovered the fuel contaminated with carbon matter as well as water. I emptied the fuel and cleaned the tanks really cleaned. I then flushed both the fuel line as well as the intake hose with alcohol and then run air to completely dry the hoses. I then bought a used canister and a new fuel pump assembly both from e-bay. I said a prayer and started the car successfully. I was hearing some sound from the fuel tank that I thought was abnormal. So, I was trying to install Tech. The car engine died on me while leaving work one Friday evening. I had nowhere to park the car and I think driving the car a little longer must have drained the battery pack. I towed it back home. It is my belief that the fuel pump quit working because of the loud noise it was making. Plus, it was way too cheap ($100 instead of $420 from Toyota). Now the car can’t start. I am afraid I drained the battery pack too low to allow it to start. Is there a way to charge the battery pack? used my OBD 2 and it is pulling away too many codes, but it says the battery pack is healthy. Any ideas where to start?