Oxygen Sensor Help

[suprajim]

Hello everyone. I am new to the forums and needed some help. I have searched and couldn't locate any other posts that answered my question. The Check Engine light on my 92 Turbo is on and I did the diagnostic check and got Code 21. So I replaced the oxygen sensor with a new 3 wire Denso. I pulled the EFI fuse and also unhooked the battery when changing it out. The plug was broken, so instead of going to the junk yard or dealership to find another one, I just cut the plug off and used butt connectors and crimped the wires together. I hooked everything back up and the light is still on and I still get Code 21. The wires at the sensor seem ok, but not really sure if it could be a problem on the other end. I'm not really sure where the other end of the wires actually leads to. Is there something else I should check? Should I trace the wires back and just try to completely replace the wiring? Any help would be appreciated.