1994 Toyota Pickup Oxygen Sensor R&R

For the chap who has the '95 Pickup; if he used the supplied BOSCH 4-cavity interface connector, it's quite possible that the lack of continuity is in THERE. The connector is impressive looking, but has terrible connection. Try a direct splice with soldered connections & shrink-tubing.

Now for mine - the factory apparently rounded off the 12mm nuts on my O2 sensor studs (I'm the original owner), so I get to "crack 'em off". The question. Are the nuts a special type, also - as the studs appear NOT to have threading on the exposed 1/4" (above the nuts), are they standard thread or some special threading?