After some digging:
https://www.evolutionm.net/forums/ev...d-problem.html

...I've bought the OEM Mitsubishi sending unit (switch) and the oil pressure sending unit socket from Autozone - but I can't seem to fit this past the axle onto the switch's housing to pull it off.

Anyone with an IX replace these notoriously bad units, without pulling the axle out? The socket's easily 4" long and even with the A-arm and axle sunk all the way into the car, I can't seem to get the axle out of the way. (I'm on Swift Spec Rs and Bilstein HDs if it makes any difference).

Also - instead of the special oil sealant, will teflon tape be ok on the threads? TIA!

 

If you have an air wrench pull the axle out of the hub but leave it in the transfer case - it isn't that much work. Plus, you have the opportunity to grease the splines so next time it isn't rust welded.

Teflon tape works fine but you must be careful. Wrap the tape too close to the end of the threads and a piece could shear off to travel in the oiling system.

 

I recently did this switch from the top of the engine. I was changing and checking the (looped) throttle body coolant hose on the back of the block. it was a tight fit, but I was able to do it. I did not remove the axle, or even jack up the car. I bought the socket from napa, but it is probably the same socket you have. remove the intake hoses, and you can see it mostly. if you change your coolant hoses back there, it makes it easier to get to the switch, but not necessary. I also used Teflon tape. worked perfectly.

 

Ah, you've got an VIII, the IX's sensor isn't on the back of the block, they moved it to the oil filter housing, something to do with MIVEC needing the block's oil pressure to actuate the variable valves.

So, I wound up using vise grips with the wheel off and the inner fender pulled back - tricky as the sensor had corroded to the filter housing, and I didn't want to use heat here. Much PB Blaster later and the switch finally came out.

I also used Teflon tape, being careful to keep the end of the threads free of any excess. Back up and running.

Thanks guys!