There are levels to this. If you decided not to follow a specific Generally Accepted Accounting Principle (GAAP) guideline, like parts of ASC 606 (revenue recognition), the auditor might accept this as long as you have a rational policy and reason for the decision. Or, the auditor may give you corrective journal entries and guidance on what your accounting treatment should look like going forward.
If you intentionally manipulated numbers with the purpose of making them look more favorable or did something even worse — like committing outright fraud — you need to come clean. It will be better for you in the long run if you are honest and explain what happened. The more you push this off, sidestep the issue or obfuscate, the more the auditor will dig in their heels. There is no good ending here if you try to hide things. The issue will not go away, and the sooner you address it, the more easily and quickly everyone can move on (and hopefully there are not significant consequences).
Auditors are not bad folks and are not looking to cause trouble or “find things.” They want a smooth audit, just like you do. The more you can assist them in making their job easier, the sooner they will be out of your hair.