Originally Posted by svvg

Yep.... I've always had to cut the wire off, then smash the ceramic part of the sensor with a hammer - but this then allows me to use a six point/impact socket plus a 2ft breaker bar on the nut...

Make sure you retap the thread before inserting the new sensor though (I ruined the threads on a new sensor by not doing this first last time I did it...) - an O2 sensor tap is only about £7 for a decent one in the UK...

On the basis that you'll have to go to a shop as it currently stands, then you may aswell give it a go...

Obviously use PB blaster/similar penetrant and as its an exhaust, it can take a fair amount of heat. I am about to change some more and will try using map gas and a blow torch - but the O2 sockets always seem to open up/slip when I use them to remove sensors. Only useful for tightening back up...

Smash the sensor body off and then use a six point socket and a breaker bar...