old O2 sensor rusted in

[Sonic dB]

Sometimes the easiest jobs become the hardest.

Im just trying to replace the old O2 senser in my 86...and the old one is NOT coming out. Ive tried wrenching it...tapping it with a hammer... Liquid Wrench + WD40.

My mechanic is out of town until the 15th... so I cant take it to him and I dont want to take it to anyone else who would over charge.

Stupid question...but does anyone have any recommendations on how to get this old O2 sensor out of there? Should I use Propane?

Thanks

[mb911]

Propane won't work. Here is the deal. If badly rusted you may have to simply twist the o2 sensor out and this will damage the threads as well. There are new bungs as they are called(threaded portion) avaible from many suppliers pelican may even have them. Then after you get the new bung have someone weld it on after it cools apply the anti-seize that is supplied with the new o2 sensor and tighten down. You also may have luck with and oxy-acetylene torch as this is hotter than a propane torch but I have not had good luck with this method on cats in the past. good luck

Ben
77 911 3.0
75 914-6 2.7

[joecrum]

I'm having the same problem with my '82. Will the O2 sensor removal tool help? The biggest problem for me is that if I try too hard to torque it off, I fear my knuckles will be bloodied.

[Sonic dB]

mb911 that solution sounds rather complicated and Im hoping not to have to resort to that...but thanks it may have to be that way.

Joe...I torqued the hell out of mine but like you was concerned about slipping the wrench and banging my hand.

Will a garage have tools which are better equipped to remove this?

As I mentioned, my mechanic is out of town.

I have seen the O2 sensor removal tool...it looks like a big socket. Im not so sure that this will work.

* Will driving the car for a couple of weeks without the O2 sensor hooked up possibly damage the engine (3.2)?

[targa80]

I have read many posts where people disconnect the O2 sensor. disconnecting the O2 sensor will put the system in an open loop status, so the frequency valve will operate at a 50% duty cycle. This will make your car will run richer than normal. When connected and operating normally the duty cycle would be between 45 ~ 55 % depending on conditions.

[Sonic dB]

Thanks Pat...so it sounds like there is not that much difference between going Open loop and having it in place (+/- 5&)?

[Early_S_Man]

db,

To free up the rusted threads ... you need to heat up the threaded area up to cherry red a nd let air cool down again ... for two or three heat-cool cycles before attempting to break the old sensor free. Oxy-acetylene rig is the only way to achieve the cherry red heat level ... AFAIK ...

No frequency valve on a DME/Motronic engine ... but disconnecting will make the DME go full-rich as during the first two minutes of the warm-up cycle.

[ruf-porsche]

I believe the 02 sensor thread is the same as that used by most spark plugs standard thread which is 18x1.5mm metric (at least that is what was used on my brother Audi V8 Quattro), so if you screw up the thread in the cat converter get a spark plug thread chaser or tap to retap the thread.

[Sonic dB]

I dont want to mess with heat, because I live in an apartment complex with lots of nosey neighbors who will not appreciate a guy with a torch in the parking lot.

Is there a way to maybe cut the old one out with a dremel tool or something?

[Groesbeck Hurricane]

I removed the CAT and clamped a large vice grip onto it. I viced the CAT so it could not spin. I then applied heat from a propane torch and was able to turn the vice grips. It was tough, but doable. I would hate to remove this on the car.

[marcesq]

Just remember no matter what you do . . . . DO NOT use any products that have silicon in them (WD-40, some anti-seize stuff) or you will be replacing the new O2 sensor within days. The new sensor should come with copper based lube.

My 2 cents

[mb911]

There is no way just cranking on it will they come out. You will have to try what early s man suggested. I have done this in the past and it sometimes works and sometimes doesn't. I am a welding instructor at a local college and have a good concept of proper heating methods so I can't claim that I didn't heat them up properly. They are just SOBs to get out but heat will be the only way out .

Ben

77 911 3.0
75 914-6 2.7

[Sonic dB]

Would it be easier to "Cut" it out...and then chisle out the threads?

[rogwilson]

i had the same problem removing my O2 sensor on my 1980 911, i put so much torque on it that it twisted off the sensor leaving the threads behind. next tried a chisel and easy-out to no avail.

trip to my p-machanic and $75 later took care of the problem. he had to remove the cat and was able to apply heat and remove the threads. he said heat was the only way to remove stubborn O2 sensors.

good luck!

[targa80]

Not knowing what the 86 has for controllling the enrichment I was assuming it was somewhat the same as what I have. I stand corrected. Thank you Early_S_man for the correction.

[Sonic dB]

Question: If my car is now "Full Rich" as Early S Man says....that cant be good!

From what I understand, there is a way to override the DME and manually set the richness/leanness on the controller box.

** Should I manually adjust it to be leaner????

Anyone?

[Sonic dB]

UPDATE::

I bought the black O2 sensor removal socket + 18" breaker bar + PB Blaster.

Gave it a shot of PB Blaster. Let it sit for a minute....stuck the socket and breaker bar on it....leaned a little and BAM... its came right out!

Very little effort actually! Never underestimate the value of physics and torque.

For you guys who are having trouble getting your o2 Sensors out, try this method first!

Sonic

[mb911]

Glad it worked for you! I have never had that kind of luck but we deal with different climates in Wisconsin everything rusts!
Ben

[Sonic dB]

Hey, Im from Detroit so I know what you mean mb911. Actually, I was a little surprised at how easy it was... ultimately its the breaker bar that makes the difference.

[mb911]

Good deal. Hey I take it you have power again? Or weren't you affected?

Ben