i bought this off a member here, it's supposed to be off his EVO that only had 23xxx miles and never modded.

what do you guys think happened?

 

looks like it was running very lean or leaded gas. That and it has no threads left.

 

what would make the threads look like that?

 

Looks like a mix of cross threading and melting. And the sensor looks like a lot of leaded fuel.

 

what would u guys do with it?

 

throw it away. Cant do anything with it without threads.

 

looks toasted, its not going to do you any good.

 

U could try to fix the threads mine on my 02 housing stripped out when i pulled it out i just ran a dye down the threads and it straightened them out enough that when i put it back in the new 02 it ran itself right in the stainless housing helped make the threads also. But i dont know how this one will read after being so messed up..probally be easier to just buy a new one.

 

Retarded and lean at WOT (WG open) will make the sensor look like that

 

Fix the threads as posted above with a Die and hope that you have enough threads left to get it in and tight so that there are no exhaust leaks. If exhaust is leaking past it you will hear it and also that means oxygen is sucking in as well throwing your o2 readings way off and you don't want that.
Word of advice is to use some anti-sieze on the threads of the o2 sensor weather you are installing that one or a new one so that it will not happen "next time" as there is always a "next time".