yes you can..but read forum rules first..get more information..google is your best friend..then open threads..this is wrong section..

if you want to downgrade via e3 flasher, make sure you have a nor chip and check the model of your ps3. Also, if you don't have much experience than it would be better that you let someone else do it for you!

I prefer Ebay Downgrade Service although its around 50-60 Dollars, i wouldn't downgrade unless you are willing to play paid games free either buying them from game stores and returning them or download games few days early from websites such as ffsinder, PS3 Iso and if you are into Real Time Modding using a DEX CFW on Rebug