Stuck O2 Sensors

DiscoGreg

Member
Dec 4, 2017
12
4
Pittsburgh PA
2003 Disco 2 SE7, 130,000 miles, 4.6 V8

Hello team - Im at a loss to get my two upstream sensors out. Ive tried from the top and bottom, WD40 every day for a week, with every wrench and socket, specialized O2 socket, heat from a propane torch and no amount of swearing will get these front two to budge. The Drivers side has such limited room to get any thing on it with leverage. The Downstream ones came out with heat and a pipe wrench.

Outside of dropping the Y pipe, any other suggestions?
 

K-rover

Well-known member
Jan 15, 2010
2,055
26
Raleigh, NC
I had the same issue a while back. Ended up cutting the pigtails off and using a regular deep socket and ratchet. The special O2 socket and wrenches didnt work.
 

Howski

Well-known member
Oct 19, 2009
1,140
72
Greenville, S.C.
Might be worth dropping it by a shop who can put it up on a lift. Had this issue on my 02’ so I took it to a shop and they were able to get it out
 

jastutte

Well-known member
Nov 10, 2009
289
16
WD40 is not penetrating oil.

as suggested above, try a true penetrating oil, cut the wires and use a true socket over the entire sensor.
 
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Agent

Well-known member
Jun 20, 2007
667
0
WV
Last O2 sensors I changed were extremely stuck. I ended up heating them with a cutting torch until they were glowing orange. They finally broke loose then and even that took some muscle.
 

lordhelemt

Well-known member
Dec 18, 2010
56
3
I had the same issue a while back. Ended up cutting the pigtails off and using a regular deep socket and ratchet. The special O2 socket and wrenches didnt work.
Ditto

Had a similar problem with a stuck o2 the wife’s lr3 earlier this year. Ended up cutting off the end of the sensor, used a 6pt deep well and ratcheting breaker bar. It still took a bit of effort but was finally able to break it loose. Never would have been able to remove that particular sensor with an o2 socket
 

DiscoGreg

Member
Dec 4, 2017
12
4
Pittsburgh PA
Well thanks guys for the suggestions. I gave up on trying to muscle, heat, PB Blaster for it for the last 8-9 days now. I cut the pig tail and used a super long 1/2 extension and socket but by this point I had rounded the edges and no dice. So - I dropped the Y pipe down enough to start air-chiseling it out only to find out, I think the previous owner welded the O2 in! So stands to reason then why it wouldn't budge.

So, I've decided Im going to pull the Y pipe out and fight now more rusted nuts and bolts.... Already having issues removing the cross-member bolts due to more fun rust.

Thanks all for the help!
 

mlnnc

Well-known member
Mar 23, 2008
217
11
Charlotte
Kinda defeats the purpose of the anti-seize that's supposed to be applied to the O2 sensor threads ...
 

DiscoGreg

Member
Dec 4, 2017
12
4
Pittsburgh PA
Hello all - I did give up on the old down pipe. I opted for a whole new Catalytic Y Pipe (Magnaflow) and got it installed pretty easily. The old one, as I suspected did have two tack welds on it. I suspect the previous owner(s) may have stripped the threads and gave up on repairing. Good news is I have no more CEL (had 10 codes previously). All new plugs, wires, coil packs, Cats, O2's and its running well......

EXCEPT for the fuel leak that just started off the back of the engine!! I will have to take the upper intake off, I suppose, to see whats going on in the back of the engine and fuel rail.