Hello I need to replace the O2 sensor uptream I tried but is stuck and now is bold, this is the picture. I put WD-40 couple of time, I put brake fluid + acetone to try to remove the rust but is impossible, somebody has the experience to came off a bold upstream sensor?
any advice will be welcome....
thanks

 

Crank the car and let it run till manifold gets warmed up…..shut it off and stick candle between manifold and Ox sensor…keep pushing it into it as it melts. Idea is to get the wax to wick up the threads. Might have to do it 2-3 times. Then try it while its hot. If it ever moves, it will come out

QUOTE=tomasorta;917389]Hello I need to replace the O2 sensor uptream I tried but is stuck and now is bold, this is the picture. I put WD-40 couple of time, I put brake fluid + acetone to try to remove the rust but is impossible, somebody has the experience to came off a bold upstream sensor?
any advice will be welcome....
thanks
[/QUOTE]

 

A long handle 7/8 wrench should have worked, but I see the O2 sensor is rounded off , possibly visegrip pliers or a propane torch to warm the threads , have a close look at the exhaust manifold, is there a crack developing in the valley

 

[/QUOTE]
Ok thanks so much for you advice but what kind of candle? Regular one? I have to put around the base of the sensor on the manifold? And that work?

 

Any kind of paraffin wax. Short piece of dinner candle works well cause easier to get in areas.

Right between the OX base and manifold so it will travel up the threads. I would let it get hot enough to “cook off” the other stuff so it will wick it better. Then if its to hot might have to let it cool some if its just vaporizing the wax….you will see. Fire extinguisher handy be good just in case.

 

By letting the car run and heat the manifold up….it heats and expands the whole manifold and the Threaded hole for the OX sensor….thats what you want.

be patient….might take 2-3 cycles.

Used this same method to remove steel exhaust studs from aluminum heads on aircooled vw’s….best trick I have found

 

but I can run the car without the shield protector over manifold?, so that is not problem> and other question I can heat the base oxigen sensor with a heat gun too? or at least to help become more hot?, because you mention have a fire extinguish in hand that scare me!!!, jaja

 

A heat gun won’t generate enough heat , the fire extinguisher is suggested as a precaution, you can start the car and run it for 5 or 10 minutes to heat up the sensor.

 

Trying the old school wax trick may have worked on the VW aluminum/metal stud removal. For this HHR problem it would probably be easier to just use a good penetrating oil. PB blaster or such should do the trick.
I would still try the heat it up method too.
Your biggest issue is getting a good "bite" on that old sensor that you buggered up.

 

Agreed, FMG , I would probably be removing the exhaust manifold by now and getting a better grip on that sensor.