Hopefully this will help others with this question.   I keep a decent inspection of my engine, change the oil, and am mechanically above average but I don’t get the issues with exhaust and induction leaks.  I’m told by a highly reputable mechanic that I have some small exhaust leaks where the pipes fit together and an induction leak where the seals are not particularly tight. I’m just wondering how having some minor leaks is an issue.  What are the advantages of having everything perfectly tight