corruptUSBOSXdd:Permission denied

diskutil list
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                                                   *4.0 GB     disk2
		(type name is blank, I did not forget)


also worth noting, if i unplug and re-plugin the usb stick, drive size shrinks:

diskutil list
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                                                   *8.4 MB     disk2
		(still no type name)			(size is shrunk)


Oddly I can reformat this shrunk drive:

diskutil eraseDisk FAT32 UNTITLED MBRFormat /dev/disk2
Started erase on disk2
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Formatting disk2s1 as MS-DOS (FAT32) with name UNTITLED
Error: -69850: The chosen size is not valid for the chosen file system

oddly I now have a type name

diskutil list
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *8.4 MB     disk2
   1:                 DOS_FAT_32                         8.4 MB     disk2s1
							(still shrunk)

Although i don't 8.4 MB is really declaring victory...;)

when I try the solution from https://apple.stackexchange.com/questions/220711/how-do-i-fix-a-corrupted-usb-drive-on-os-x/220719?noredirect=1#comment462336_220719 on full size drive everything goes fine until the last step

sudo dd if=/path/to/UNTITLED.dmg of=/dev/disk2 bs=1m
Password:
dd: /dev/disk2: Permission denied