Many users face different itunes errors when it comes to restoring their devices. The steps to fix any error 16xx during a custom restore is very simple. all you have to is to follow the steps below to help you perform this process. The guide below was performed using Mac OS X, the same process can be used on a computer running Windows operating system.
Double click PwnageTool dmg file to mount it.
Click and drag the PwnageTool icon to Pwnage Folder you created and then open it from there.
Warning Box will Popup. Just hit the OK button.
Make sure you select Expert Mode from Top menu
Select your device i.e: iPhone 3G. A big Green check mark will appear on the selected device.
Now hit the big Blue Arrow button at bottom right to proceed.
On the next page, PwnageTool will automatically find the IPSW file. If not found then click “Browse for IPSW” button and select the downloaded IPSW file: iPhone1,2_3.1_7C144_Restore.ipsw. A check mark will appear next to it.
Then hit Blue Arrow Button to proceed.
On the next page you will have 6 choices. Select the General and hit Blue Arrow Button to proceed.
On the next Page you can decide your Root Partition Size where OS resides. Click activate the phone (if you’re on unofficial carrier).
***For the 3.1 firmware you may have to increase the size of your root partition slightly for the IPSW build to be successful. 695MB worked just fine for me***
The Bootneuter settings are greyed out for the iPhone 3G. Click the blue arrow button.
The next screen will show the Cydia settings menu. It allows you to create custom packages so you do not have to manually install them later.
Go to Download p
ackages tab.and hit the Refresh button to display all the available packages. Double click your desired package, it will be downloaded and will be available under the Select Packages tab.
When you have downloaded your desired packages, go back to Select Packages tab and check mark the ones you want.
Click on the Blue Arrow Button to proceed.
Custom Packages Settings will displays listed package settings for your custom IPSW. Leave these settings as is for now. Just click the Blue Arrow Button to proceed.
On the following Custom Package Settings menu, select Cydia Inslaller and Icy if not already. After that, follow the on-screen instructions.