o2 sensor impossible to get out

Hey guys, as the title suggests I'm trying to get my o2 sensor out in order to pull my stock dump pipe out but this thing is nearly welded in there. I'm looking for any kind of advice from you guys that have upgraded your exhaust and ran into the same issue.

As you know space is at a premium and it is impossible to get anything of any worth on the sensor, I have a proper o2 socket, ive tried driving and heating it up. I don't want to use a blow torch because of the location of the pipe, someone at nissan obviously didn't care about ever pulling this ute back apart ever.

Are there any secrets that I'm missing that I cannot see because i'm that over it, the socket just spins on the o2 sensor now if you try too hard with a massive breaker. The nut is still in tackt just has minimal rounding.

Yeah, mine was awfully tight as well.
I ended up being able to get a spanner onto it (open ended both ends), then used a ring spanner on the opposite end of the open ended spanner for leverage.

Once it was cracked, it came out fairly easily, however you need to keep flipping the spanner to get some movement. As you know, it is very tight.

do you have to remove this sensor to get the dump pipe off ? sounds to me you don,t so just remove the dump and with the help of a vice etc then you can easily remove the sensor from pipe.

It's very tight in the engine bay of the 550s because they squeezed that v6 in there, I know we don't always need to follow the manual but it does say to remove the o2 sensor and having tried to jig it out with the sensor in I don't think it is possible at all, the dump pipe is too twisted and the o2 sensor just hits on the engine.

If anyone has managed to pull out the dump pipe with the o2 sensor still in I would love to know how as I'll be giving it a go.

if this is the case you will need to heat up the 02 sensor plug hole and spray it with wd-40 a few times . i would heat up and spray then do it again a couple of times so its heated say 3 times and sprayed 3 times , use a piece of fibro or whatever as a sheild if this makes you feel safer using heat down there plus make sure the spanner your using is a perfect fit if no go use a good set of Vice Grips, these will hold the nut part very well when done up tight.

I managed to remove dump pipe with the o2 sensor still in then put it in a vice so I could hit the spanner with a hammer. It was a tight fit and took some patience