Cordless impact recommendation?

[Chryco Psycho]

I bought the Milwaukee Fuel 18 v impact 2861-20
I guess something is wrong with it , it would not undo a wing nut on an aircleaner , I can stop it turning with my fingers 

Neil, I stand to be corrected, but I believe they have variable torque settings, so maybe yours is set on "creampuff" LOL 

I have to look it over more closely , right now it would not hurt a paper AC filter tightening the wingnut so it has to be set on less than finger tq if it has an adjustment at all  !!