The whole of the dialogue does not need to be redone. Only a handful of some phrase maybe should be. But there are words that sometimes do not make sense, or are simply the wrong word. Example 1, MC and Cathy walking to Cathy's dad's, MC says "valley" instead of "alley".
Example 2, at the Cathy pool sex scene, MC talks about how Cathy's is getting horny but says "I'm" instead of "you're".
Things like that. There are others but these are fresh in my mind. Dialogue/text just needs some clean up.