So, following my post about my O2 sensor codes I decided to change the rear O2 sensors.... bad move!
The front ones had previously come out with out so much as a bead of sweat..
The rears... cracked - turned about 1/4 turn and promptly stuck!
After much shouting and they eventually came out... but the threads in the exhaust are fuggered!

Will now have to drop the entire system off the car (easy eh!) and try and tap out a new thread.

Anyone else had this problem? The o2 sensors looked factory - so well over 7 years old now.

New o2 sensors on order for tomorrow.

Any advice re the exhaust? Thanks! Range Rover Vogue 4.4 (2003)

the exhaust is not as hard as you think to drop off the car. Just support it as best you can when undoing the nuts.

the re-fit was the hard part as its heavy and a tight fit in terms of tolerances of lining up bolts to holes on the headers. Again, having it well supported up to the car, but being able to shuffle it around when supported is the key.

It just slides out from underneath the car ... my thread with pics is here of a weld repair on the cat box...

http://rangerovers.net/forum/viewtopic.php?f=2&t=32757 V8 or else ...

If the thread is not too , you can get a spark plug thread chaser and redo in situ. You'd need one that can be turned in the middle with an ordinary wrench (spanner ). 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

I know the feeling, i turn an oil change into hard job. Last year i rounded off a sump bolt, then broke an easy out on it leaving that stuck in the bolt...... Had to call a mate in the end, he welded a bar to it and it shifted.

Thats why i'm a draughtsman, i'm good at the technical stuff in theory only...  2004 black Vogue TD6

Sealey do a cat thread chaser £4.00... only snag 4 day wait!

Did it with an M18 tap in the end. Range Rover Vogue 4.4 (2003)

Exhaust is back on the car now, just about to re-fit the new O2 sensors and see what happens.

I dont think its going to cure my problem myself... but its the last option now really as I have tried almost everything else I can think of. Range Rover Vogue 4.4 (2003)

Fault codes have gone which is good.

However - my fault is still there.

I will post another thread about it... Range Rover Vogue 4.4 (2003)