Hi everyone, I'm a bit lost so I have few questions about downgrading. I got an iPhone 4 running iOS 7.1.2 that I want to downgrade to iOS 6 because iOS 7 is too slow on that iPhone 4. I've already searched on internet but I found a lot of different tutorials so I have some questions : -Can I yes or no downgrade my iPhone 4 without SHSH ? -If yes, will I be able to use it as a phone or iPod only (I've seen in some tutorials a No Service error when you put your SIM). -I saw that downgrading will jailbreak the phone on tethered jailbreak but I can remove this jailbreak or simply make it untethered with a Cydia tweak ? Thank you very much for answers.