Anti-seize compounds and Catalyst poisoning?

[Omahaug]

Does anyone happen to know whether certain anti-seize compounds should not be used on any sensors upstream from the catalytic converter?

I'm questioning whether some have metals in them that can poison catalysts. Does that even happen?

I have two kinds, I have the good ol' Loctite copper AS and the silverish one from Permatex. Both say fine for oxygen sensors but neither say anything about A/F sensors that usually sit upstream from the catalytic converter.

I'm assuming if anyone did make it past the threads like on the housing below the sensor cage itself, it would burn up and just leave metal dust. Not sure if the metal dust would do anything to the catalysts.

 

[Trav]

AF monitor = Wide band O2 sensor. If its okay for O2 sensors its okay for AFM.

 

[JMJNet]

When I bought the Denso O2 sensor (A/F Monitor), they always come with Antiseize in a single use tube.
It is like copper colored not sure what type it is though.

I am sure that if you use any antiseize sparingly, it should be fine.

I usually just put a dab at the beginning thread and then it will smear evenly as the part is threaded on.
I even thread it on and off a couple of times before tightening it to evenly spread the anti seize.
Make sure that it goes only on the threaded portion not the sensor portion of the part.

 

[slacktide_bitog]

Originally Posted By: JMJNet
When I bought the Denso O2 sensor (A/F Monitor), they always come with Antiseize in a single use tube.
It is like copper colored not sure what type it is though.


+1

the anti-seize they come with is fine and will not do any harm

 

[nthach]

It's silicon that will poison an O2 sensor - which is why you must use "sensor-safe" RTV if you reseal an engine. Burning old school green coolant can also kill an O2.

The trace amount of crystalline silica in anti-seize isn't enough to hurt things.

 

[lilred67]

I install O2's and 3-way Catalyst at work and we use metal free anti-seize ( recommended by the catalyst manufacturer ) on them to avoid poisoning.