Q: How to tackle errors that have not been mentioned by the peer reviewers?
My paper received a decision of Accept with Major Revisions, and I am currently working on the revisions. During the revision process, I found that there were other scientific mistakes that the reviewer hadn’t commented on. Although the Discussion and Conclusion of the paper remain unchanged, I am worried whether I should withdraw the paper because of these problems. Or is it okay for me to resubmit the paper to the same journal with a detailed explanation for the revised parts (based on the errors I found by myself)?
It's good that you spotted the changes needed in your manuscript before it has been accepted for publication. Even though the discussion and conclusion remain unchanged, it's important that you bring any changes you make to the notice of the editor and peer reviewers. Since your manuscript has received a decision of accept with major revisions, there's a good chance it will go through another round of peer review. You don't need to withdraw your manuscript at this point --- assuming the errors you have spotted don't drastically change the essence and impact of your findings. In your resubmission cover letter, you should explain the situation to the journal editor, and in your responses to reviewer comments, provide a detailed account and explanation of the changes made.