Are you using the hackmii installer? you should do, you need to re install hbc and bootmii as boot 2 if possible.What steps have you followed so far?
No I have a PC
If you formatted the Wii trough the System Menu, you probably lost precious IOS.
With that in mind, it's best to wait for some input from Maui or some other credited Moderator.
The only thing I can tell is it doesn't matter if it's at v4.1.
You still can use the games exploits (although it should have worked with BannerBomb. That's the whole point of this Guide Downgrading the v4.3 Wiis to v4.1).
But, like I said, if it's not working with BannerBomb, maybe something's missing and it's best to hear for other people.
Are you trying to use the game exploit?