Replacing o2 sensors
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Sure, "Lefty Lucy", counter-clockwise to loosen. Now and then something badly seized will "crack" free, clockwise. (like a zillionth of a turn), then unscrew. I've had that work. Also if your "bolt" head is stripping you might get what you need to crack it going in, then unscrew it.
Roler, if you can get ahold of some Kroil, and keep it pickled for a really long time, week or two, that might help.
Roler, if you can get ahold of some Kroil, and keep it pickled for a really long time, week or two, that might help.
CF Veteran
Joined: Jan 2012
Posts: 3,170
Likes: 312
From: Australia
Year: 1997 (RHD)
Model: Cherokee (XJ)
Engine: 4.0 ltr
I marinated my sensors in a wide variety of loosening agents till the point my driveway was a darn slippery slope....I tell you, I think I tried it all.
I suspect, esp with my cath one, that they welded it in there when they changed my cath converter...
I suspect, esp with my cath one, that they welded it in there when they changed my cath converter...
Banned
Joined: Feb 2014
Posts: 2,379
Likes: 18
From: Florida
Year: 2000
Model: Cherokee(XJ)
Engine: Golen 4.6L
O2s are so easy to place. Have done my uppers about 3 years ago and finally did the lowers recently, when I did the lowers I replaced all 4. Drive for 30mins. Get the pipes nice and hot. Use an open wrench. Then you can slowly massage it open. That's all there is. Th lowers I was on my back on the floor. The uppers you can get from above or below
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
My jeep has 4, that's why I mentioned that I replaced all 4. He mentioned he was o my doing his 2. He has it easier with just 2. Do it half the time it took me
CF Veteran
Joined: Jan 2012
Posts: 3,170
Likes: 312
From: Australia
Year: 1997 (RHD)
Model: Cherokee (XJ)
Engine: 4.0 ltr
I'm having this same issue today. Had some serious stuttering and sputtering. Did a tune up ( needed it anyway.) Cleaned throttle body....still crap. Remembered I had an obd scanner for my phone- ( no cel on my dash- burned out?) Scanned and said o2 heater fault. Crawled under there and the entire harness is crushed and split open. *rolls eyes*.
Couldn't get the sensor out so I spliced the wires and replaced my fuse- still running crappy. Think my sensor is shot. Gonna blast it with PB and follow this thread.....its gotta get fixed! (My DD!)
Couldn't get the sensor out so I spliced the wires and replaced my fuse- still running crappy. Think my sensor is shot. Gonna blast it with PB and follow this thread.....its gotta get fixed! (My DD!)
CF Veteran
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Just "sharing" stuff I saw here. (Me and my Renix..well, one has no memory. If you leave the battery disconnected over night, that should clear the puter. Hands down. Then It will re-learn over like, the next 40 cycles. Somewhere in some FSM it advises the teck to take it for a drive to do the first couple of cycles, since it may suck right away. Maybe with the fault fixed it just needs to clear it's throat! 
For sure..sharks spit out surfers, right on the wave!

For sure..sharks spit out surfers, right on the wave!
Newbie
Joined: Apr 2013
Posts: 20
Likes: 0
From: Virginia Beach
Year: 1997
Model: Cherokee
Engine: 6.0 4L
Hey guys. Dont post on here that often but always reading! Ive been trying my upstream for about 4 days now. The wires are cut, soaked in PB and have tried torching and using an O2 special tool. Nothing has worked yet and now its almost to the point of being rounded. Im like 99.9% sure its not reverse threaded. Any other ideas?
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Is the 02 socket 6 point or 12? If it's 12 you might cut the wires to get a six point on it....On my Renix I cut the wires and got it pretty easy with a 7/8 Box wrench. (12 Pt.)
Senior Member
Joined: May 2014
Posts: 672
Likes: 5
From: Colorado
Year: 2001, 1997
Model: Cherokee
Engine: 4.0L
Some of the cheaper O2 tools are made from cheap steel that expand when you put torque on them. The ones from NAPA are 6 point and about $6 and not the greatest with regards to expanding, but they do work. I've found it pretty easy to remove O2 sensors when the engine has been run for a bit and then cooled down enough to work on it. A box end or similar should also work. Try to heat up the exhaust pipe if you were heating up the O2 sensor. If its too rounded a hammer and cold chisel may help.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I myself have never seen or used the "correct" tool. If it has a slot on the business end....I'd be inclined to chuck it. The "tensile cohesion" of steel is nutty high. If the wrench does not circle the nut, all bet's are off. You can bend it, but stretching steel is a different issue.
Anything stuck like that, with all the torque you can apply, rap the (7/8 Box) wrench hard with a hammer. The shock + the torque is way better then ether alone.
Worst case might be hammering/fitting a smaller 6 point socket onto it. Idk,13/16 or maybe something metric. Gotta be out there on some forum.
Anything stuck like that, with all the torque you can apply, rap the (7/8 Box) wrench hard with a hammer. The shock + the torque is way better then ether alone.
Worst case might be hammering/fitting a smaller 6 point socket onto it. Idk,13/16 or maybe something metric. Gotta be out there on some forum.


