Restore iOS Without Updating (Jailbreak Required): If you want to restore your device to its current firmware without having to update, all you have to do is follow these instructions.
This process corresponds to remove the Jailbreak (Unjailbreaking) by restoring your iOS device to a fresh installation (like it comes from the store). Actually we published a tutorial some months ago explaining how to Unjailbreak iOS 8, in this post we are upgrading all the information and explaining the differences to iOS 9.
You will need to keep in mind that this will only work if your device is already jailbroken, because you will have to use a Cydia utility called Impactor that will allow you to do this.
Download and Install Impactor Utility in iOS 8 / iOS 9
Step 1 (for iOS 9): the first thing you will want to open Cydia > Go to “Sources” tab > “Edit” > “Add Source” and add this: “http://apt.saurik.com/beta/cy-impactor/“.
Note: if you get this error “POSIX: Operation timed out” don’t worry: tap “Cancel” then “Return to Cydia“.
Step 2 (for iOS 9): in the Sources tab tap “apt.saurik.com (http://apt.saurik.com/beta/cy-impactor/)” > “All Packages” > “Cydia Impactor” > “Modify” > “Install“.
Step 1 (for iOS 8): if you are on iOS 8, you don’t have to worry about adding the source. All you have to do is go to Cydia > “Packages” tab and search for “Impactor”. Then tap on “Modify” and then “Install”.
Once you have downloaded and installed Impactor, you will find the application on your device. Open up the Cydia Impactor app. Make sure you read all the instructions before proceed. When you are sure > tap “Delete all data, unjailbreak device”. This process will take a while (20 ~30 min estimated).
After this process is done, you will see the standard “Hello” screen, and you will need to go ahead and set up your device. Go into Settings, General, and About just to see that you are on the same operating system.
How to Uninstall Impactor
If you want to remove Impactor app you will no be able to remove it directly from Springboard. Instead, you’ll need to open up Cydia > go to “Installed” tab > find Impactor > tap “Modify” tap “Remove“.