I was chasing down a light rattle and decided to inspect my cat. converter in case i has some loose pieces within it. Turns out that everything is in great shape with the cat., nothing loose in there. The secondary O2 sensor looks pretty good, it has some whitish deposits and only a very small bit of black carbon on it. Is there any benefit to cleaning it before I reinstall it ?, if so I'll do it, if not then I'll just reinstall it. Thanks for any replies. I've got 55,000 miles on the original cat. and O2 sensors for an 02MY.

 

No, just leave it alone. No one sees it anyway.

 

yeah definitely not a cosmetic part, just wondering if it would run better being a bit cleaner, probably not worth the time though as you mention. thanks for the reply.

 

You cant really clean an O2 sensor you just replace them, it will get build up with carbon after all as its in the exhaust stream.

Wont really do anything unless it really really caked/covered in carbon, just leave it IMO.

 

Cleaning it will usually kill it. Chemicals, and even water should be kept very far away from it, both on the sensor side AND the wire side. IIRC the backside is used as a reference.

 

yeah that is a good point, I better stay away from it then. thanks for the advice.

 

The wire side of the O2 is on the outside, it will get wet driving through puddles one would think.
Not that I would clean it though.
Maybe spray some contact cleaner on/in both plugs if they are dirty.
Thats it.
Allthough.. sometimes there is some white or creamy looking "grease" on the contacts in those plugs to stop corrosion.

Its mentioned in the other O2 post you have: put some neverzees on the threads.
(But NOT on the O2 itself)

Btw.. are you sure the rattle is not from the cat?
Because I had a MY00 cat with the cores loose enough to shift and rattle.

 

thanks for the reply. I might give it a light wipe to get any loose carbon off, but I will avoid any fluids on it. I will definitely be using anti-sieze on the threads. I disconnected the cat completely and took it out so I could get a good look at it. I shook it and inspected the internals, it is pretty solid. I'm thinking the light rattle might be timing chain tensioner as I've eliminated the cat as one source.