So I recently traded in my 2003 evo8 for a 2006 evo9 se. i noticed that the under the car someting was hanging down. i looked and what do you know...its the rear o2 sensor that plugs into the cat converter. well i was going to put it back in, but it didnt seem to want to go back in....look at the picture of it and let me know what you think is going on. i have no idea what the hell happened. the car is stock with 31k miles on it. only thing modded is roispec lowering springs and window tint. trying to keep the car under remainder of warranty

 

The o2 sensor is supposed to have threads on it to screw in, from that picture I dont see any threads. Is it under that thing that looks like its wrapped by a tape of some sort?

When you tried to screw it in did, was there a plug on the o2 bung of the exhaust?

Are you throwing any CEL lights?

If your not throwing any Check engine lights then most likely the car is tuned to by pass the second o2 sensor. So you can leave it out just as long as its still plugged in and zip tied securely of course.

 

not throwing any CEL. im not sure what it is wrapped in seemed like clay or something. didnt want to try to break clay off or damage the sensor. car is all stock i highly doubt it's ever been tuned..

 

weres the threads? it looks like somebody over tightend it because the threads are missin and u can kinda see it was tightend hard or something

 

pull off exhaust and c if the thread is stuck inside? then you would have to tap and die it out and but a new 02

 

If your not throwing any CEL light then that means the car is tuned. Otherwise if you take an o2 sensor out and drive the car it will trigger a CEL light.

That "clay" thing is not supposed to be there. So remove it and see if the threads are under it and if so try screwing it in.

 

remove the "clay" or whatever it is and try to screw it back in

 

clay seems to be stuck on or something. im not sure if its clay but it feels like really dry clay. also the fact im not throw a CEL is weird....

 

Thats because the car is tuned. Either the previous owner had a tactrix cable and used a labtop to turn off the second o2 or the car is/was tuned for more power and the o2 turned off in the process.