I use the Cura; nylon default(recommended) settings for PETG. Upon my filament's box is written 200-240 for nozzle and 75-85 for bed. So I tried 245/80 - 220/80 - 220/60 - 245/60.
But I got same result as you can see in the pics:
My printer is PrusaI3 (actually a chinese kit that I assembled it myself). Also I had good print results with PLA before this. I was using 190/50 for PLA).