ICQ>

1. Soak with Liquid Wrench or a non-silicone-based penetrant for a good day beforehand, and cycle the exhaust through a warmup to try to get the penetrant well down. I use Liquid Wrench, but find PB Blaster better at tough jobs. Try removing it when the exhaust is warm (not hot), but with a ice-cube held against the sensor threads to cool it down and maybe thermally break the bond. Watch the sensor wrench, since they are split down the middle and can bend. Also, try removing with a breaker bar on the wrench, banging the bar end with a hammer using small but sharp strokes.

2. The sensors come pre-coated; don't use additional anti-seize. Don't get anything with silicone anywhere near the sensor (or the intake system, for that matter:) it will contaminate the sensor. Don't use dielectric grease on the sensor connector.

3. Never used them; don't know.