What to check with OBD2.

Instrumental?

I don't know.

Unscrew the trough with the wiper motor, unscrew the spark plugs and look at the condition of the cylinders. Visually!
On the Prius GEN2, the engine often eats oil, but not coolant.

 

I have not used such devices, so I can not reliably say about this possibility.
The cooling system has many components. Engine, radiator, heater in the cabin, thermos for keeping hot coolant, pumps, taps, hoses. Where to connect the device?

 

The top is secured with several clips.

 

Yes, you can

 

I think the Prius probably won't be a right fit for you look for a Yaris It's a reliable Toyota same engine is the Prius almost similar gas mileage You might not notice the difference to be honest about it unless you've got a lot of driving to do If you're not going to keep a Prius in the wind as in your nice person in the seat you might want to look at something that's better suited to you if you're going to work and parking the car in the sun all day while you're in work doing whatever you probably don't need a Prius to be honest about it so there are things like that you've got to get worked out internally You're looking for guarantees and you're not going to find them with a scan tool generally speaking The scan tool is generally used for when something is wrong and there are lights on the dash and things to go with that and you have a capable scan tool that will read all 21 computers in the Prius that you're looking at then you get information I don't know whether that will help you buy the car or not most Prius of this genre that you find are sitting in the tow lots and sitting in people's yards for sale for a reason like the ones you're talking about not dealing with That's why I buy them for 5 and $700 because I know what they need and I'm going to put it on them and drive them to 600k most people aren't looking to do that they're looking to have a cool cute little car for a little while and sell it so they can buy a generation 3 a generation 4 of Volkswagen whatever they're doing so you know I don't know people personally don't really care about all that a generation two is quite a superior car to a lot of other vehicles but with that superiority comes some interesting maintenance many people don't need to be up for the interesting maintenance they could just buy a Yaris or a Scion XA and I could go on and on and get nearly the same thing without the special maintenance problems. So obviously you want these problems or something because this is what goes with the territory I don't know how many generation twos you're going to walk up to that are going to be in near mint condition offering the price you want to pay with a very good hybrid battery the brake actuator already replaced and all the other little things already done more than likely that person would be keeping that car so there's always these things not understanding and being able to interpret some of the readings like the high and low voltage for instance You don't even know if you're looking at high and low 12 volt voltage or something to do with the hybrid battery I can't see your scanner from here so there isn't learning curve to learning how to use the scanner and what it is speaking to you about some people have this interest most do not most people really don't have any interest in working on a car even their car they just want it to work and be able to say I have a such and such and so and so and it works great whatever. Just by the questions and what's happening here. I would recommend you look at a Scion XA or a Yaris You will be a very happy camper they're good cars they're not keep up with the Joneses type cars but they're very solid reliable vehicles that I personally have driven into the 400,000 mile range and looking decent while doing it You may do something different matter of fact like an almost assure you that you will.

 

Do NOT buy an old Prius unless you can fix any problem that may occur by yourself. If you need someone else to fix a problem, it will be a very expensive car to keep running.

Base on what you have posted in this thread, I advise that you do not buy an old Prius.