I am putting headers on my car and my o2 sensors look burnt up. Do they all look like this or are mine crapped out? My gas mileage hasn't been all that lately so who knows?

 

That's what mine looked like and they work fine.

 

What you can see is simply the vented metal shield around the sensor... you can't see the actual sensor element. No way to judge condition from the photos.

Whenever I have done headers, it just seemed logical to replace the O2 sensors at the same time, assuming they have 30K or more miles on them. Particularly if you had to use a lot of penetrating oil to get them out.... that can contaminate the outside of the sensor.

 

i actually didn't have to use any penetrating oil to get them out at all. It was basically pretty easy. Except for having to find a 7/8th wrench. So, I'm guessing it's logical to just replace the o2s. I assume when the headers are on, it's a real bitch to replace considering how akwardly placed they are.