What to look out for in 2004 Prius?

2004's are tanks. that said, it's important that the hybrid battery is new, oem, not reconditioned or rebuilt.
of course, any car that age can have substantial 4 figure repairs needed at any time, that you cannot detect now. as well as normal things like shocks, struts and etc.

reset the trip meter and take it for a good long ride under varied conditions. listen for odd sounds, and check to see what she returns for mpg's.

do they have the complete maintenance history? any accidents?

how will you know if it's an oil burner?

 

If you plan on parking this car on the streets of Los Angeles, the catalytic converter will probably get stolen again. So if you don't have a garage space, you should just pass

 

One of the common fails on the second gen Prius is the brake accumulator pump. some of them never fail others do. You buy remanufactured ones now for about $600.
I would take it for a decent test drive reset the trip and MPG and see what it gives you. Always a possibility that's an oil burner but that's true with any car, and quite frankly oils cheap. the risk of having the catalytic converter stolen again I guess is true but that's the same on any other car also. perhaps more so because there's not much room under the Prius they would definitely have to jack it up to get under there.
I personally like the interior on the second gen a bit more even in the third gen. I think the material quality they used was a little bit better. You don't get quite as much information as you do on a 3rd gen as far as efficient driving. It doesn't have the little meter that goes from braking to eco the power..
however there are apps you can get on your phone to connect to an OBD2 Bluetooth connector. And you can get some of that information that way if you choose. If you have one of those devices already you can use dr Prius app to do some battery testing. The one I use on a daily basis is called hybrid assistant, it can help you drive more efficiently mostly it can help you brak more efficiently. It also gives you some temperature readouts on engine, inverter, mg2, battery, and it will allow you to override the cooling fan speed profile. I live in a hot climate during the summer. And I have it set to override and go to the maximum cooling at 115 degrees Fahrenheit. Keeping the battery cooler can extend its life.
If the car runs and drives well, and she's not asking that much for it I don't really see what you could lose. But I don't think I would pay more than $5,000 for it. $3k would be better.

Posted via the PriusChat mobile app.

 

coincidentally, someone else just posted that they are looking at a 2004 with 200k, with a dead 12v.

 

I wouldnt pay more than 1500 for it to be honest