"Justice" seems to show a pre warp civilization, and possibly "Code of Honor" too.
...While, in contrast, no episode states or suggests that pre-warp civilizations should not be contacted or interacted with. Indeed, say, the word "warp" is not uttered a single time in "Pen Pals"!
Then again we see on multiple occasions that the Prime Directive means that the Federation would rather sit back and watch a culture die than aid them if they are unaware of alien life.
I can think of just two examples of such: "Pen Pals" and "Homeward". And in the former, nobody actually suggests sitting back and watching the Dremans die; it's merely a case of Picard calling for a philosophical debate on what they are about to do before they actually get on with it, lest anybody think that the PD could be automatically
As for "Homeward", the lack of technological sophistication or awareness of interstellar politics by the Boraalans is never mentioned as affecting Picard's decision not to interfere, one way or the other.