Rumble, Smoke and P0300

Hello everyone!

I was hoping I could get some advice and help or direction here. After doing a bunch of searching this seems to be a fairly common occurrence with older Prius's.

My car went very close to empty and I had just put gas into it. About 20 miles down the road the car rumbled a bit and stalled out.

After towing the car there is now a rumble when turning on. Now the car is smoking white smoke out of the exhaust and under the hood.

I'm getting codes P0300, P0302, P0304, P3190.

I have seen many different ideas on what this might be. I changed the spark plugs out. No luck.

 

Old spark plugs were TRASHED. They were all burnt and rusted looking. One has slight oil on it.

MPG was reading around 40ish I believe. Below where it once was, not by much.

the rumble did happen once when I was sitting idling with the AC on. It rumbled for maybe 15 seconds and went away for maybe 3 weeks until this happened

I did get the red triangle but the codes were the same misfiring codes which would pop up at random after only longer drives. Maybe after 15/20 miles or so

also.. not sure if coincidence but it seemed to coincide with warmer weather

 

Is there any way to test for water in the gas? What are my options if that's the case?

same w the coolant. How do I check or fix this?

coolant was low, I filled it. A lot of smoke but coolant looks to be same level unless it's burning a lot of smoke with barely any coolant