A book about two siblings(?) scrapping junk in a wasteland
I don't have too many details about this books since I read it back during grade school, but I'll update if I remember any more details.
It was a YA book about two teens who are either siblings or good friends, a boy and a girl, and one of the two finds some illegal tech that would sell for a lot or help them somehow. I think they wanted to repair it. The world was usually described as polluted and grimy, and they lived in the slums with one guardian. At one point in the book they're in some sort of facility trying to find a piece of tech(?) and are chased by the bad guys and have to hide to escape. I don't think I got very far into the book since I don't have any idea what happens after that chase scene, but I'm pretty sure it was part of a small series.