Question on Jailbreaking to 4.2.1

[Gmas]

So I have a 3GS and previously jailbroke to 3.1.2 with PwnageTool probably a year+ ago now. My phone still has the original 4.26 bootrom and everything went totally smooth with my initial jailbreak process.

Recently I've run into issues where some new apps need 4.0 or above to run so I think it's time to upgrade my f/w. Just want to confirm with the experts here with the best way to do so. I've read about Greenpois0n, but it seems there's now a reliable jailbreak solution with PwnageTool where I can upgrade to 4.2.1 f/w with PwnageTool 4.2

Is there any reason why I shouldn't use this method? Is there a better way?

 

[bookwormsy]

pwnage tool and greenpois0n are both great tools. the only problem would be if you didnt save your shsh blobs via cydia (if you said "make my life easier" in cydia you'd be fine) because i dont think apple is signing the 4.2.1 blobs anymore.

 

[Gmas]

pwnage tool and greenpois0n are both great tools. the only problem would be if you didnt save your shsh blobs via cydia (if you said "make my life easier" in cydia you'd be fine) because i dont think apple is signing the 4.2.1 blobs anymore.

Thanks for the response. For my situation is either PwnageTool or Greenpois0n better than the other?

Also, with PwnageTool I'd be looking to make a custom 4.2.1 firmware upgrading from my current custom 3.1.2 - I wouldn't need shsh blobs saved to do that would I??

 

[Applejuiced]

Thanks for the response. For my situation is either PwnageTool or Greenpois0n better than the other?

Also, with PwnageTool I'd be looking to make a custom 4.2.1 firmware upgrading from my current custom 3.1.2 - I wouldn't need shsh blobs saved to do that would I??

Yes.
Without shsh blobs you can only restore to the latest 4.3
Open up cydia and look at the top of the page if it has shsh: listed.

 

[Gmas]

Thanks Applejuiced.

Just checked and it lists SHSH for 4.0, 4.0.1, 4.1, 4.2.1+

So with that confirmed, will the process be more or less identical to when I jailbroke my phone with PwnageTool the first time? Just using a different version of PwnageTool and different firmware this time.

 

[bookwormsy]

use these instructions: http://www.saurik.com/id/12#howto

that will redirect itune's request to cydia so it will give itunes the blob so you can restore. if you dont do it, it will fail.

 

[Applejuiced]

Thanks Applejuiced.

Just checked and it lists SHSH for 4.0, 4.0.1, 4.1, 4.2.1+

So with that confirmed, will the process be more or less identical to when I jailbroke my phone with PwnageTool the first time? Just using a different version of PwnageTool and different firmware this time.

Yes, you're good then.
Either edit your hosts file on your computer to point to Sauriks server like the bro said or use Tinyumbrella and click "start TSS server" before you open up itunes to restore to the custom pwnagetool 4.2.1 ipsw.