Legal Question in Criminal Law in California

Are you asking if you can withdraw a plea on an old case? Typically, the answer is no. There is a very short time period to withdraw a plea or request a sentence modification.

You can seek expungements under Penal Code section 1203.4 if you qualify or other post-conviction relief, but it depends on the case.

If you're trying to attack or undo an old plea or conviction, then your options may be limited, but a habeas corpus motion may be appropriate.

The answer depends on when you plead, what you plead to and why you're trying to undo the deal.