iPhone 3Gs cannot upgrade?

[6thDAY]

hey guys, I'm having an issue that I cannot seem to resolve. I've looked at all the solutions online for the errors itunes were spitting out and none seems to work.

I have a 3gs 32gb on firmware 05.11.07 with firmware 3.1.2. The firmware is stock, non-jailbroken without cydia. I'm trying to upgrade to 4.3.1. I cooked the stocked firmware 4.3.1 to get a custom one.

I tried leaving the phone on without DFU mode and when I tried to restore using right-click, itunes says it is "preparing iphone for restore" and then my phone reboots. It shows the apple logo and goes straight to recovery mode with the itunes logo.

I tried putting it into DFU mode and did the restore again, but it still goes into recovery mode.

I am using the newest version of itunes.

I have tried many times, and itunes keeps throwing 1600, 1602, 1604 errors.

Thanks

[iYeow]

You can only restore to 4.1 or 5.0 cos you were not jailbroken before.

[6thDAY]

I just jailbroke it through blackra1n and tried upgrading to 4.3.1. Now its popping up with errors 21.

[iYeow]

Why do you want 4.3.1 ? You need saved shsh blob. Apple now signs 4.1 and 5.0 for 3GS

[6thDAY]

I do have saved SHSH blobs for 4.3.1. I originally was on 4.3.3 but it was too slow, so I was trying to downgrade to 4.3.1 because some apps I use require at least 4.3, but when I tried to downgrade using tinyumbrella, itunes put my phone into recovery mode and I couldnt get it out of that mode. This is when I restore to stock 3.1.2 firmware and tried to upgrade, and the errors mentioned popped up.

And I thought you didnt need SHSH blobs for updating? only downgrading.

[iYeow]

4.3.1 is the same as 4.3.3 , 4.3.2 supposed to solve battery issue, 4.3.3 is to stop apple monitor your personal location. 4.1 will make a difference in speed compared to 4.3.3