Might be a dumb question but I got a 2000 honda civic lx, been driving with a bad o2 sensors for awhile now, thought id try to get rid of it for once. The only thing is i need is to extend my o2 sensor about an extra 16 inch to reach my headers since my o2 sensor sits down below, but when i cut the wires they were silver? Was kind of assuming for copper but not sure what kind of metal it is, is it safe to just twist the copper on and heat shrink it? Any ideas on what might the wiring material may be and how to do the job right?

The o2 sensors i got were Bosch.

 

You have already cut the wires, so I would just try and solder to them. I would have gone to the junk yard and see about getting the engine harness side wires of the O2 and then your old O2, using those wires and making an extension harness that just plugs in and you go. I did that for my 07 Si being their splice job failed and the after market exhaust moved the sensor a bit farther down the header from stock. No harness or O2 sensor wires need be cut and it's easy to return to stock formation if ever needed.

 

Do not just twist wires together. The signal wire from the O2 that runs to the ECU is a shielded wire. You MUST keep the shielding separate from the conductor.