Why on earth this o2 sensor too tight in my car.. I bought an 22mm especial socket from ecp to remove it, but no luck. I had special wrench (for metal pipe working). It just damaged the nut but didn't make it move. Used WD40, but no luck. Now ordered 'Autojack 5 Piece Oxygen Sensor Sockets & Thread Chaser Set' from B&Q for home delivery.. Don't know if this kit will be of any help to unscrew this............ senaor. 

There was nothing wrong with sensor. Just have decided to give it a little cleaning while waiting for New car batrery delivery. Recently consumption seems too high, someone  suggested me tio give it a little cleaning.

1 hour ago, automass said:

Why on earth this o2 sensor too tight in my car.. I bought an 22mm especial socket from ecp to remove it, but no luck. I had special wrench (for metal pipe working). It just damaged the nut

 

Harsh environment, even when you get a decent tool you may find you have hampered yourself with the damage done using the pipe wrench.

 

B&Q is not the place I would be looking for a higher quality tool after another has failed.

 

Was it a split socket you used or were you able to disconnect the cable? 6 point or 12 point?

Split socket i bought from ECP (pic attached). I found it too long that my breaker bar (ratchet) wouldn't fit in the tight space. So I ordered other kit from B&Q. See pic. B&Q doesn't sto k them in the shop. They do deliver only. I thought i would be needing the smaller split socket so my ratcher bar can fit. while i was waiting for this kit from B&Q, I just wanted to try with pipe wrench.. Now the nut got damaged. Hence why, I was asking if anybody else had the similar issue removing this o2 sensor..and how did you do it. 

They go through a lot of heat cycles, so they're always tight. Best bet is to get the blowtorch on it before you even start trying to remove it. 

 

It's not best practice, but - If I'm not planning on using the sensor again, I've been known to stick the Stilson's on the body of the sensor. Worst case you snap it off and leave the nut at a convenient length to put an impact socket on. 

my plan is just to give it a good clean and use it again. That's why I don't wanna damage it.

Cleaning the surface you can actually get at when it is removed will make no difference. 

You're wasting your time on a guess.

Best to remove o2 sensors after running engine/exhaust hot. Probably not safest to work on, depending on sensor location, but they do come out easier and without additional heating.

I use a slotted impact socket with a breaker bar then a ratchet, impact sockets tend to be beefier/stifer than regular sockets.

Main problem is getting the right impact socket that fits the sensor, a lot of them fit only thinner sensors and are not suitablle for Bosch o2 sensors which have a thicker body.

Have not removed any O2 sensors on the mk3 vrs yet, but did remove a couple on other cars.

Finally managed to open both of them. It was right, hot is the proper time to open it. it was very easy to unscrew when it was hot. now time to give them a good clean. i think with engine degreaser or any other rust cleaner would be ideal to clean them.