I'm am playing Ratchet and Clank: Up You Arsenal and need infinite health?

I have heard that you can use x,x,r2,r3,l3,l2left,up but it doesn't work. I there a certain place that I have to enter it at or is it just a fraud? Or if you know one just tell me. I know all about the laser sword instead of the wrench so don't tell me about it.