02 Sensor Removal

[M.T.Wallet]

I'm having trouble taking off an 02 sensor in my GMC.I have been soaking it with pb blaster but it does not seem to cut it.I'm trying to avoid using a torch because I don't want to harm the sensor.I was told that they can be saved if they are cleaned off and reinstalled.If a different penetrant is better I'd like to know of it.
Thanks

 

[Ramblin Fever]

How many miles you got on that sensor? If you're over 70k and it's giving you issues, just replace it. I've never heard of cleaning off an O2, either they're good or they're bad. But, I could be wrong.

I just got done replacing all 4 on my '97 Rodeo with 153k miles - it took a lot of arm power, and there was no saving them, they didn't break off, but they were mangled by the time we got them out.

Try warming up the engine a very slight tad, might help, but don't get the exhaust too hot or you'll pay dearly with your forearm.

 

[porcupine73]

I always find it a pain to get out the O2 sensors. I put a little Kroil (penetrating oil) and tap it and let it set for a while.

I think the real secret is to run the engine for maybe a minute or two and then try to get the O2 sensor out. Heat expands the pipe and bung? Of course you must be careful of hot exhaust pipes and stuff.

If I can get a wrench on, I disconnect the connector and slip a 6pt (or 12pt if need be) wrench over it and just keep pushing and pulling on it until the thing loosens up. A little more Kroil. Start it and run it again a minute or two. Eventually it will come out.

I've never used a torch, but it might be alright to do so; the sensor probably sees 1000+deg F temps anyway.

As I'm sure you already know don't torque too hard on the thing or you could mess up the bung.

You might consider just replacing the O2 sensor; I always get better vehicle operation with a new one if the thing is old.

 

[porcupine73]

Oh don't forget to put antiseize on the threads of the O2 sensor when replacing it if you ever want to be able to get it out again.

 

[M.T.Wallet]

Where can I purchase "Kroil" ? I live in Michigan.

 

[porcupine73]

There was recently a thread on Kroil here . I bought a gallon can of Kroil from KanoLabs.com. You have to put in a business name during the checkout.

I used Kroil on my last O2 sensor replace, but what really helped was running the engine for a few minutes and then wrenching on it. It was the warming up that finally let me get the thing out.

 

[GMBoy]

No need to put antisieze on the threads as all new Ow sensors already have it installed. But if you reuse your sensor (not recommended) than, yeah recoat with antisieze.

 

[bdcardinal]

i bought a set of O2 sensor sockets from MATCO. makes the job a lot easier.

 

[mechtech]

Maybe it's time for a new sensor. If so, break off the top of the sensor, and use a six point socket [after soaking with penetrating oil].

 

[JTK]

The ~$25 tool kit from www.oxygensensors.com has helped me out several times, especially if you can fit a breaker bar on the socket. Excellent prices & service @ that site. All else fails, do like mechtech says, rip the barrel off the sensor & attach the hex base with a socket/wrench. If anything it will be easier to work with the the top off.

G/luck
Joel

 

[chas3]

not the first choice, but if there is clearance stick a well made flare nut wrench on the sensor and hit it with a hammer (or find a length of pipe) to break the o2 sensor free.

 

[Propflux01]

On my '81 grand prix, it had teh origianl sensor installed. In 2004 I changed it. all I did was warm the engine up, and it came right out. i was told by someone that that is the only way to get thm out, and it worked. been there for 20 years, and used no penetration oil or anything but a wrench.

 

[Bret Chase]

I did my O2 on my 88 K2500a couple of weeks ago... I drove it for 7 miles (from my apt to the shop at work), put my 7/8" box end wrench on it and pushed really hard, and busted my knuckles all to ****. It came out like nothing.. I was amazed, as this sucker was 17 years old. now when I changed the O2 on my old G. Voyager.. I had to take the box end wrench, piggy back another wrench on it, spray it with deep creep AND PB B'laster and pull like ****. it fought me the whole way. I've got an "O2" socket, but I only use them to put the new one in.

 

[got boost?]

if you've gotten any oil on the top of the sensor it is trash anyway. you can't clean sensors, you CAN test them however. you need a digital voltmeter and a propane torch. do a search on google for specifics. I would plan to replace the sensor because usually when they are that hard to get off, the threads get ruined. regardless, if the sensor has thrown a code you WILL NOT be able to fix it so you have to replace it. and btw, if you let it go it will ruin the cat.