Removing rusted O2 sensors

[chicane]

I am having trouble removing my post Cat O2 sensors. I have a solid 22mm wrench that is made for removing O2 sensors, and I soaked well with PB Blaster and heated up the sensor before hand, but when I tried to wrench it off it just rounded sensor's plug bolt sides.

Any help is appreciated.

 

[owenst7]

I am having trouble removing my post Cat O2 sensors. I have a solid 22mm wrench that is made for removing O2 sensors, and I soaked well with PB Blaster and heated up the sensor before hand, but when I tried to wrench it off it just rounded sensor's plug bolt sides.

Any help is appreciated.

Heat expands metal. You need to heat the female threads, not the male threads. If it's completely rounded now, you're probably going to have to use a pipe wrench or weld a lever to it and hit it with a hammer.

 

[jayoldschool]

 

[Stooge]

if its getting replaced anyways, can you just cut the pigtail off and convince a deep impact 7/8-22mm socket onto it? maybe let the car run for a few minutes prior to get the exhaust nice and hot to make it a little easier

 

[CobraRed]

They should really just make these plugs out of stainless.
I find before even putting much torque on a rusted one, i go the wrench and hammer method and it seems busting them loose works much better than just slowly applying force to leverage.

 

[bcradio]

pliers wrench

 

[ClineWrench]

I used to deal with this stuff constantly (especially on F-150s). Here what you do.

First Wd40 the **** around the threads and let it soak in for just a little but. Then heat up the pipe around the O2 sensor. Sometimes it helps to wrap the O2 sensor in tin foil,to resist heat. You want the pipe got and the O2 sensor cold (or as cold as you can keep with while working around it with a torch).

Then get a vice grip on it and turn away. Should come right off. Whatever you do, don't heat up the sensor itself. I've seen them expand and become super tight and difficult it remove.

 

[quattroJoe]

...and put some anti seize on the threads of the new sensor, if there isn't already (Bosch sensors have it applied out of the box.)

 

[wafrederick]

Sometimes the threads will get damaged in the bung and is real easy to fix.Running an 18mm x 1.50 tap will clean the threads up after letting the bung cool down.NTK oxygen sensors have anti sieze on the threads out of the box.Bosch oxygen sensors are a waste of money,they fail a lot and I have seen this happen brand new in the box

 

[theoldwizard1]

...and put some anti seize on the threads of the new sensor, if there isn't already (Bosch sensors have it applied out of the box.)

Cooper high temp anti-seize.

 

[sweetk30]

fyi the 18x1.50 tap is the same as the old 2 ended spark plug thread chasiers .

but if to bad yes need a tap .

worst local exhaust shops should have weld in bungs to replace then with . 5 bucks give or take for new bung then weld in .

 

[jacob_coulter]

The right tool makes a big difference, I really like using this style, it's harder to round off

 

[treblarefils]

I have used this tool a million times it works sometimes but on really stubborn O2s the socket spreads and just rounds off the the sensor.

 

[byoungblood]

I've always had good success with a deep offset double box end wrench and a dead blow hammer. An actual striking wrench would probably get the job done too. In any case, this method works well since many times you can't get an impact on one.

 

[1949 caddyman]

I have a Snap-on socket that looks like a line wrench end. It has a slot for wires & the sensor. http://store.snapon.com/Oxygen-Sensor-Socket-Oxygen-Sensor-7-8-22-mm-Hex-3-8-Drive-P643914.aspx

 

[Skyline]

I like the impact crow foot type O2 socket. Once the area is heated red hot with a torch as suggested above, you can bang on the offset tab (where you would normally insert a breaker bar,) with a BFH and that will do it. I've had plenty of rounded off failures with the type of socket Jacob suggested.

Caddyman...you typed faster....that's the one I'm talking about.

 

[davesnothere]

If you're replacing it anyway, cut the wires and put a regular socket on it.

 

[92integra]

if you have rounded it off i will offer some suggestions.... cut the wire and smash a slightly smaller 12 point socket onto it and impact it off, nut extractors will do the same job. air hammer with a chisel attachement hammering it in the correct direction will help, can be accomplished with a regular chise and hammer as well..... knipex cobras can bite into that thing with incredible force and long enough one's should give you the leverage to spin it out.... and if you day is really really bad you might just have to drop the exhuast to be able to work that thing out. and same as all other's above have stated heat is your friend and chasing threads and anti sieze will help this from becoming and issue again. GOOD LUCK

 

[peteco]

CRC Freeze-Off has worked well for me. Sometimes it takes 2 or 3 applications before things break free.

 

[nicksnothereman]

I am having trouble removing my post Cat O2 sensors. I have a solid 22mm wrench that is made for removing O2 sensors, and I soaked well with PB Blaster and heated up the sensor before hand, but when I tried to wrench it off it just rounded sensor's plug bolt sides.

Any help is appreciated.

1/2" junker ratchet and o2 sensor socket. Deadblow or cheater on the ratchet handle if it won't go after the heat and penetrating oil.

 

[ClineWrench]

I Once saw my co-worker weld a junk socket to an O2 sensor on a 97 thumderbird then using his ratchet with a wickedly long cheater, bust loose what must have been the rustiest O2 sensor I've Ever seen.

So when in doubt, use heat. When in dispair, weld.

 

[chicane]

Right because every home mechanic has an acetylene torch.

 

[oldjamesy]

I Once saw my co-worker weld a junk socket to an O2 sensor on a 97 thumderbird then using his ratchet with a wickedly long cheater, bust loose what must have been the rustiest O2 sensor I've Ever seen.

So when in doubt, use heat. When in dispair, weld.

I've done the same thing with a wrench out of absolute desperation , and it worked . Lucky for me

Tightening them just a touch before loosening has been a good method for me as well .

 

[jayoldschool]

Right because every home mechanic has an acetylene torch.

They're under 400 for a portable set. If you're doing work that needs a tool, buy the right tool.

 

[unslow1]

I have used this tool a million times it works sometimes but on really stubborn O2s the socket spreads and just rounds off the the sensor.

If it starts to spread you can put a worm gear style hose clamp around it. Usually I just cut the wires and use a socket or box end wrench.

 

[FunkyfullWidth]

Right because every home mechanic has an acetylene torch.

Every home mechanic that plans on doing alot ofexhaust work should. 02 sensors can be a bear to get off. Sometimes it's easier to drop the exhaust, assuming everything else isn't rotted.

Essential tools to removing exhausts, IMO.

Twist sockets
Deep impact swivels (For studs)
TORCHES
Drill
Drill bits
Taps and/or thread chasers

Heating up exhausts to remove o2's can be tricky, you don't want to twist the exhaust pipe instead of removing the o2. When it fits, a good pipe wrench. Or drop the exhaust and use a good pipe wrench and the heel of your boot.

 

[chicane]

They're under 400 for a portable set. If you're doing work that needs a tool, buy the right tool.

I have neither the room, nor the expertise, nor the need to keep such a tool on hand, there are other ways.

 

[joetool]

I have neither the room, nor the expertise, nor the need to keep such a tool on hand, there are other ways.

I use a simple hand torch whenever I need to apply heat. Run about $50.

 

[ClineWrench]

Bingo Joe. Same approach I take. Except I got mine at ace hardware for $26 bucks.

 

[thesilverone]

so did you get the 02 sensor out yet?

 

[lakota]

MAPP torch was good. MAPP been out of production for years, so the stuff they claim is MAPP is not the true old stuff.

Quote: "In the spring of 2008, true MAPP gas production ended in North America when production was discontinued at the only remaining plant making it. Current products labeled "MAPP" are in fact MAPP substitutes. These versions are stabilized liquefied petroleum gas (LPG) with high levels of propylene."

link: http://en.wikipedia.org/wiki/MAPP_gas

 

[shockwave]

Best thing is get the benzomatic 2 part and heat up cherry red with adjustable wrench as it will com out easy and heat up the area around threads and not the hex so much

 

[deter]

my trick is to try to TIGHTEN the sensor first to break it loose. Then reverse it.