Dan, I'd say no, she didn't. I haven't found any mid-1942 picture of U-166, but in the pictures of Type IXs taken at Lorient in late 1941 and 1942 none of the boats sported the net cutter anymore (U-166 arrived in Lorient on 10 July 1942 and left for her first and last patrol on 17 July 1942). U-166 was launched in 1942, by that time net cutters had already been discontinued on type IX boats.
Cheers
SG