... When its probably been there for 15 years
Underside is actually quite clean, no rust and very little dirt. Nevertheless I couldn't budge the o2 sensor at all. I don't have a 22mm spanner (will be picking one up tomorrow) so I tried a pair of vice grips and giving it a few love taps with a hammer, won't budge.

Because its directly on the exhaust i'm afraid of bending or damaging something. Are they normally very tight? should I be taking any precautions in regards to not damaging the exhaust in the process?
Any tips/tricks to getting it out, particularly because its on a very craptacular angle thats hard to get leverage on

Also, the cable side. I got the rubber seal off but the cable doesn't seem to want to feed through. Does it need to be disconnected from within the engine bay first? if so, whats the best angle to get to it?

They can be tight, if you are buying a tool to do this buy a proper sensor removal socket, will work much better

When you crack the sensor dont just go hell for leather and unscrew it as there will be carbon on the thread, undo it until it starts to get tight, back it off and repeat, may take a few minutes to get it out however this will crack the carbon off the thread thus not damage the thread in the pipe

Cable is connected under the dash, take off the side trim from the console and the metal plate, you will see the 4 wires. You also need to remove the white plastic bit as well in the floor

... When its probably been there for 15 years
Underside is actually quite clean, no rust and very little dirt. Nevertheless I couldn't budge the o2 sensor at all. I don't have a 22mm spanner (will be picking one up tomorrow) so I tried a pair of vice grips and giving it a few love taps with a hammer, won't budge.

Because its directly on the exhaust i'm afraid of bending or damaging something. Are they normally very tight? should I be taking any precautions in regards to not damaging the exhaust in the process?
Any tips/tricks to getting it out, particularly because its on a very craptacular angle thats hard to get leverage on

Also, the cable side. I got the rubber seal off but the cable doesn't seem to want to feed through. Does it need to be disconnected from within the engine bay first? if so, whats the best angle to get to it?

Use the right tools and it will come of easy, vice grips are not the right tool, an o2 sensor tool or a decent spanner will make easy work of it.

Use penetrating fluid or warm the exhaust up first to make it easier to remove.

I did a DIY on this check the DIY forum, the sensor connects to a plug near the ECU, this needs to be unplugged first.

Cheers

Madmagna it would have helped if you specified Passenger/Driver side :D, I pulled the drivers side apart and was trying to find it :oopssign:

Up here in backwards ass Cairns, nobody's ever heard of an o2 sensor socket :nuts:
Borrowed a 22mm, chopped the cable and slid it on. Took a fair shove but it came undone.

I'm yet to drive it but the car was warm and it didn't smell as badly just idling. Used to be I would swing to my car space and when reversing I could smell unburnt fuel if I had the windows down or just kept it idling for a while. I also unhooked the battery for a couple mins. Hopefully this brings the consumption down from 14-15L/100km

Madmagna it would have helped if you specified Passenger/Driver side

Thirty seconds of research would have told you that.

Thirty seconds of research would have told you that.

Well I have the verada service manual, it quite literally specifies 'removal instructions' as

X. Remove Oxygen Sensor

where 'x' is whatever number in its steps. No diagram of where the wire goes, no mention of how to remove it correctly, no mention of socket size, nothing
Do you have a better one?

Don't expect details like that in any car workshop manual - they are not a series of "how to" instructions.

Things like "how to" do an Oxygen sensor replacement, or cam belt, ancillary belt replacement, air/fuel/oil filter replacement etc just aren't in there.

Don't worry, with a few years of hands on experience and patience you get quite good at translating workshop instructions into the steps needed to actually do a task. lol

Well I have the verada service manual, it quite literally specifies 'removal instructions' as

Do you have a better one?

Like I said prior to your second response.
http://www.aussiemagna.com/forums/showthread.php?t=102388