What I would do -
Get a 22mm wrench. The one with the open end on one end and the closed
socket type of circle on the other end of the wrench.

Put the circle onto the O2 sensor.
This means you have cut the wire off already and that is fine.

Whack the box end of the wrench with the hammer.
If it moves at all, get PB blaster into the threads.
Then tighten it just a tad.

More PB blaster then use the wrench and hammer to loosen it.

The air tool impact wrench will get it off
but, you may destroy the threads in the cat pipe using an impact to simply
force it out that way.

Mine came out with a simple box end wrench.

If it is rounded, you could try very large vice grips and a hammer on the vice grips.

Don't laugh.

 

I did all of these things. Sometimes stuck is stuck.

 

Bummer... I think I'm in the stuck is stuck but perhaps a bit O' luck and a thrup and it will come out.

 

Which gasket? The intake manifold gasket?
because I’m dealing with a coolant leak, bad idle,
misfire 1-8, mainly in cyl 3 and 5.
big plume of smoke sometimes after ignition, high readings of fuel pressure, and intake manifold absolute pressure is low.
when you’re sitting in it after ignition, the rough idle rocks the car so bad it’s like you’re ina rocking chair.

i added another clamp here in the photo, cause it appears to be where some seepage coming from?
unless you guys can tell I’m missing something on this little metal flange. Also, There’s a coolant/oil puddle under my throttle bottle in the valley of the engine V…..
and i found a slight bit of oil along the flap of my throttle body last night.

also besides having a bad Bank two o2 sensor for awhile. There’s no fault codes. Just the o2 sensor code if i do highway driving.
if i do any rpm above idle, the car doesnt misfire, but i still hear an air leak somewhere.
it runs fine on the road. But with all this happening now, I havnt drivin it since.

i ordered 2 upper and 2 lower o2 sensors from autozone, they’re Bosch. May be here next week.

i’m going to be doing some more diag tomorrow after work at the dodge dealership i work at with the master tech. I’ve deeply appreciated his help but both of us are new to land rovers.

this is my personal vehicle, so i’ve been rather stressed tryna find all the info I can.
this started on Thursday Sep 22nd after work. The first day it started getting cold here in the midwest.

1 year ago, both HighPressure fuel pumps, 8 injectors, 8 coils, 8 plugs, supercharger isolator, and intake manifold gaskets were replaced, and the map sensor at back of intake. But not both map sensors

It’s a 2012 RR sport S/C with 138,000 miles. No issues in 1 year till now.. except as i said earlier, the P0430 code which appears randomly.