I'm looking for a higher mileage Prius (~100-150k miles), what problems should I watch out for?

Rectal exam: stick your finger in the tailpipe. If it comes out slightly rusty or cleaner, its perfect. If it comes out black, it is consuming oil, the cat will be short-lived. In California, you are screwed if your have a bad cat outside of 10/150 warranty.

It's really hard to get the car to trigger a DTC when there is a marginal pack. If you take it up Cajon Pass and have no drivability issues, the battery is probably fine.

 

SoC drains rapidly to 1 bar and the car will barely go.

 

If you're looking for a high mileage GenII I would be tempted to sell mine. Most of the stuff I've modified could be turned back to stock fairly easily. At least you'd know the history of the car. lol

 

...that is, if OP is willing to read thru your 11,820 posts!
OTOH OP might want to look at Sticky note about typical issues with Gen-II

 

Good point! Hahaha

 

http://priuschat.com/forums/gen-ii-...77-common-2g-problems-what-do-about-them.html

There are a lot of people that are going to dump their GII upon delivery of a PHV. It would be worth a little extra to get a well cared for car from someone here, like from andyprius.

 

Aside from mechanical factors - I found a massive variation in the interior quality of used Gen 2 when I was looking. This is largely to do with owner care, but as the inside is where you be spending your time driving, it's worth merely looking at a number of models with similar mileage to ensure you get value for money. I would even personally sacrifice a few miles for an interior that is near spotless, assuming that the mechanical elements are in order.