O2/Lambda sensor removal, help or guidance?

Hello, new guy here, but not necessarily new to Jaguar. I recently acquired a 94 Jag XJS 2+2 with the AJ6 (Signal red with black top and black interior) with the cold weather package. Car currently has about 75K miles on it.
(O2 Lambda question is at the bottom in bold if you wish to skip the backstory)
First a brief Back story, I was born and raised in Portland, Oregon. My Dad bought this car for my step mom back in 1997(then had about 40K miles on it, and still has the sales paperwork in the glove box that my Dad signed, and although they “promised” me I could drive it to my senior Prom in 99(I even had a date lined up!), they pulled that rug out from under me and I had to drive my 85 Ford Thunderbird, but they let me take pictures next to it before prom, thanks Mom and Dad! Lol. I was weird kid, I loved to wash, wax, and detail this car for them as a teenager, in hopes they would let me drive it around the block. The lines on this car are so damn sexy!
Fast forward to 2006, My Dad(My best friend and hero) passed away from lung cancer at 51 years old, I was 25yo at this time. I recall my dad had the convertible top reupholstered and maintained regularly before he asked me to take it through the car wash one last time before helping him put the cover on it in the garage for the last time. And so this car sat in my step mom’s garage, under a cover ever since that fall in 2006. When I heard from my younger brother last year that Mom was about to sell the Jag (to just “get rid of it”) for a whopping $500, I had to step in and say NOoO! So last November for my 40th birthday, guess who got keys to the non operable Jag! (it was bittersweet, but it also meant that I now had 2 of the most impractical vehicles a single father of two teenage boys, both of who are over 6’4" tall) could have, a 2nd gen dodge ram and a 94 Jag XJS. (I do find alot of humor in all of this, yes, HaHa)

Present day, and what I have done to the car since getting it to my house in November;
Fuel system: I have flushed the fuel tank twice, replaced the fuel pump, new fuel filter, new fuel regulator, cleaned/flushed and triggered all 6 fuel injectors with success(done this twice now). reinstalled after finding one injector was dead(got new injector from Jagbits, Thanks Gary!). Verified I have a good signal/pulses from the ECU with a noid light.
Ignition system: Replaced ignition coil, all 6 spark plugs(Cu plugs) and new plug wires.
She finally awoke from her 14 year slumber(was it ever a battle just to get to this point!), but still runs like crap, smell is way too rich. I’m assuming the O2/lambda sensor has failed (that and the FF44 code I’m getting), in my research on here, I read that if the O2 sensor is dead the car will run very rich. The local Jag dealership used my Vin# to verify my car only has the one Lambda sensor on the Y-pipe. I have a new O2 sensor supposed to arrive on Thursday/tomorrow.
Main question(s);

  1. What size is the Lambda sensor socket size? I have the special socket(7/8ths) with the slit and after soaking it with WD40 for a few hours, I extensioned the crap out of that socket but it wont turn for me. (the socket WILL turn, but the sensor is still tight in the exhaust pipe!)
  2. Do I need to drop the exhaust Y-pipe to get to this O2 sensor?
  3. and/or what is the easiest route to get this Y-pipe out?

Thankyou for your help,

Welcome to the group!

Any pics of your ride?
When I changed my O2’s I could not for the life of me get the thing to move with WD40.
The next day I used PB blaster and gave it some love taps. 5 minutes later came back and did it again. And again. Finally it came loose after I slid a piece of pipe onto the end of the ratchet and worked it out. Best of luck! I’ve always had better luck with PB blaster but I’m sure others will have their opinions that could be helpful as well.
You shouldn’t have to get the down pipe off to change the sensor.
Are there any visible exhaust leaks at the manifold to collectors where the Y pipe meets the manifold? This can throw off an O2 sensor big time.

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Ill try to get some more, I’m at work tonight, Graveyard shift isn’t too kind to banging on your car at 2am on lunch break, atleast there’s no HOA! Lol. Ill get some more pics up soon.

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