Is it possible to downgrade a 3GS JB 3.1.2 to 3.1 and then JB?

[ninethirty]

I have an ECID on file with Cydia.. but the 3.1.2 JB drains battery like crazy and I can't handle it anymore.

I've asked in many threads, but gotten no response, so here it is:

Can I downgrade to 3.1, and then JB my 3GS so I don't have to deal with this awful battery life?

If it's not possible to downgrade, should I just restore to legit 3.1.2 and wait for the next update/Jailbreak?

Thanks!

 

[thelatinist]

You can downgrade, as long as you've edited your hosts file to point signature requests to saurik's server rather than Apple's. I would suggest, however, first trying restoring to the custom 3.1.2 again and setting up as a new phone rather than restoring from backup. Most battery issues with upgrade seem to be traceable to restoring from backup, for some reason.

ETA: Actually, since Apple is still signing 3.1 firmware files, you don't need to edit your hosts file to downgrade. It's a good idea to do it anyway, though.