<span style="font-family: 'Verdana'">Yes I wanted to use a regular wrench, but there's no room to swing it unless I remove the transmission dipstick tube. I didn't want to take a chance on breaking that so I ended up getting one of those crowfoot style sockets</span>.
I think more important than the oil brand is allowing whatever you use the time to soak in and do it’s job. A shot of even SuperTech penetrating oil has yet to fail me if I use it the day before removal. And if you do it while hot, don’t forget the gloves and sleeves.
Spray it multiple times, over a 24 or 48 hour time period. That should help quite a bit. PB Blaster or any spray penetrator should work fine. All else fails, use a little heat. If it seizes and stops after it turns a little, turn it back in a little, blast it a few more times, wait, and commence process again. "Supertech" works fine!
I don't think the penetrating oil was doing a thing for me when I was working on my truck. The threads went too far into the cat and I am sure they were covered with 20 years of carbon. 2 came off effortlessly, but 1 had it's threads destroyed. $30 part.
Did the GM assembly guys in May of 1997 use anti seize? If so, how long does it last? I am unsure of both..
None work very well on an O2 sensor or spark plug, the fluid cant get past the gasket. You can spray it for a year and the threads will still be bone dry.
The rust comes from inside and the amount of corrosion is dependent mostly on climate and usage cycle, areas of low humidity and have higher year round temps will usually have no corrosion problems. Cars operated in short trip cycles in colder temps can have so much corrosion and carbon it can pull the threads or break the sensor or bung.
Get a deep 7/8 6pt socket and long extension with ball swivel on your car, cut the wire off and use a breaker bar or impact gun set on a lower setting to hammer it loose, heat the bung only with a smoke wrench if its not moving.
Running the engine doesn't help much, similar metals have similar expansion rates, steel sensor shell and steel pipe are expanding together when both are heated at the same time.
Oxyacetylene if they get too stubborn..Just did this last week.
I was just going to mention using torches. If you're replacing the whole sensor with a new one, why not use )))HEAT((( ? Unless you don't have torches of course!
I mean, if you are only replacing the exhaust part and need to reinstall the same O2 sensor well then, using a penetrating oil is the only way...or if you don't have torches I understand this, as I don't have them either!
How easy O2 sensors come out depends entirely on where you live. In Pa by the time an O2 sensor needed replaced it was rust-welded in and you needed every trick in the book and sometimes you'd break the manifold and create a new disaster involving rusted manifold bolts. When we came to Az I bought a 95 Cherokee that spent it's life in Phoenix, when the O2 went bad it cracked loose with a wrench and I turned it out by hand, the threads were still shiny. Had a bit of an emotional moment and realized I'd come to DIY heaven....
Merc, how humid is it in Clovis, Ca.. it can't be in that tight. Give it a few squirts over a day or two of whatever and pop that thing out.
No silicon containing penetrating oils anywhere near the o2 bung!!!
It'll kill the new one or make it read out of range and BIG BIG problem with Lamda is 02 sense is the FINAL WORD.
If Its off everything else is N.G.
MMT additive, nitromethane and a bit of Lubrimoly make a good penetrant.
My opinion is that any type of penetrating oil doesn't begin working until you break the bond and get the bolt/nut/stud (or oxy sensor in this case) moving. Else, it never actually penetrates.
I'd love to hear a true story where an actual seized fastener wasn't budging, but after a PB Blaster soak it came right out.
If it's seized, penetrating oil won't help. Heat will be required.
Also, I don't care for O2 sockets when it comes to removal. The slot weakens them and they spread/flex. I cut the wires off (it's being replaced anyway, right?) and use either a box end wrench or a standard 6 point deep socket.