I've been getting really horrible gas mileage on my 2003 Nissan Primera, and at inspection they said I seem to have an exhaust leak. So I took off the heat shield and sprayed some soapy water in various places and saw bubbles at the base of the O2 sensor. I'm assuming this means I've got an exhaust leak at that point.

So, I have a bottle of Permatex Aluminum Anti-Seize and on the back of the bottle it says it's good for O2 sensor threads, among other things. Can I just unscrew the O2, put some of this on the threads and reasonably expect it to solve the problem?

  • Copper anti-seize is a much better option, as it handles the heat better than does the aluminum. Sep 18, 2017 at 13:28
  • Did you get this fixed?
    – Tahlor
    Sep 26, 2022 at 4:47

1 Answer 1


A copper washer could be a better bet - your anti-seize is designed to stop threads seizing so as it is not primarily designed to seal them it may not, however you could be lucky and it will.

  • I agree, you want something else in there, relying on the threads might not work and if you're taking the sensor off anyway you may as well. Just be very careful not to get any anti-seize on the sensor itself.
    – GdD
    Sep 18, 2017 at 9:28
  • @Robert S.Barnes Nothing more to add here, except that you could place the anti seize on the threads (always a good idea on exhaust related things) and add the copper washer
    – Martin
    Sep 18, 2017 at 11:30
  • Would a brass washer be OK? The only store I know of in my city that carries varieties of washers doesn't carry copper, only brass. Sep 19, 2017 at 7:25

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