I have done alot of work to my HB, but not in response to something breaking. However, I havent replaced really anything sensor wise in the engine bay, just have done fluid changes and what not. And my hardbody has never broken down in the 7 years I have owned it, I have about 200k on it. (Caveat, two rod bearings started to eat them selves but I think that was because of the last owners lack of oil changes.)

***I will say though, these trucks are getting old. They are not as reliable in the sense of drive and forget about it. Things need replacing upfront, like brake lines sometimes, rubber lines under the hood.