@thejs said in Duet 2 wifi printing at 4mm/s '"PLEASE HELP'":

I added new printer in Cura-Under Machine Settings-GCodeFlavor- I chose RepRapVolumetric out of these options.

RepRap(Marlin/Sprinter) RepRap(Volumetric) Ultimaker Griffin Makerbot BitsfromBytes Mach3 Repitier

That looks like your Cura version is a bit outdated because newer versions (at least the current 4.2) have a clear distinction between RepRap and Marlin. And if you select RepRap(Volumetric) then you also have to enable volumetric extrusion in RRF via M200.

Still this won't solve your heating issues. But as @Veti said check if you have a tool selected. If that still does not help please post the contents of your config.g.