Front o2 sensor nuts are fused on, Options?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

tymeboy

tymeboy

10 Year
Joined
Mar 10, 2015
Threads
16
Messages
52
Location
West Jordan
So I need to change my front o2 sensor. I tried removing the nuts and no dice. I heated them etc and nothing. Am i stuck? Is it possible to just purchase that section of the exhaust? Or, does anyone have any other ideas on how to get the nuts off? Thanks so much I checked the FAQ section and all I saw was a conversation on a new ems exhaust and a steel vs copper nut thread.

96 Land Cruiser
 
I used the Irwin bolt extractor set. Best 23.00 I spent at Oreilly auto parts. If the extractor doesnt work, you can take a dremel tool with a cutoff wheel, and very carefully cut the accessible side of the nut in half, and spread it with a screwdriver. Just dont dig into the threads on the studs.
 
stevezero said:
I used the Irwin bolt extractor set. Best 23.00 I spent at Oreilly auto parts. If the extractor doesnt work, you can take a dremel tool with a cutoff wheel, and very carefully cut the accessible side of the nut in half, and spread it with a screwdriver. Just dont dig into the threads on the studs.
Click to expand...
Very good idea with the dremel. I just got a new one. I will have to try it out on those nuts.
 
When I replaced my o2 sensors the nuts were so rounded off that the irwin nut extractor didn't grab. I had to weld a spot on the nut to give the nut extractor some grip.
IMG_3264.jpg

IMG_3262.jpg
 
If you have an air chisel and a sharp chisel to go with it, you can split the nuts and use the chisel to loosen them.

It takes reduced air pressure and good trigger control.

Point the chisel at the flat of the nut, with the cutting edge running lengthwise on the stud. Bang it a few times to groove the nut. Increase the banging while moving the ass end of the chisel so it will effectively loosen the nut. It will start to unscrew. Stop and take it off the rest of the way with pliers or maybe even a wrench.

I've had very good success with this method, but you need to be able to come at the nuts in the proper direction, which is sometimes impossible. I had my running boards off and hadn't installed sliders yet, so the front one was very easy.
 
For future reference the studs from the early 1993-1994 trucks for the PAIR valve pipes will work for the O2 sensors:

90116-08211

Then you can use the lock nuts:

90179-08059

So you can have new studs and nuts if they are beyond saving.
 
Thank you Beno for that info. I may need to order those studs and nuts. Even though I have owned my truck since 2000, some previous idgit put JB Weld on the studs on one of the o2 sensors on my truck.
 
stevezero said:
I used the Irwin bolt extractor set. Best 23.00 I spent at Oreilly auto parts. If the extractor doesnt work, you can take a dremel tool with a cutoff wheel, and very carefully cut the accessible side of the nut in half, and spread it with a screwdriver. Just dont dig into the threads on the studs.
Click to expand...
I got the Irwin's too and then ended up getting a set of Craftsman extractors instead since they had the right size (11 mm?) and the Irwin's skipped it.

Also, lots of PB Blaster to prep with.
 
Did mine recently on my 3rd gen and they looked like this

image (7).webp


I used a Dremel with a flexible extension with a small grinding wheel. I basically cut them in half until I was at the threads, stuck a flat head screwdriver in there and hammered away. Worked like a charm, nuts came right off.

Used an M8 x 1.25 die to make sure the threads were good on the studs and installed the new sensor.
 
OGBeno said:
For future reference the studs from the early 1993-1994 trucks for the PAIR valve pipes will work for the O2 sensors:

90116-08211

Then you can use the lock nuts:

90179-08059

So you can have new studs and nuts if they are beyond saving.
Click to expand...
Hey Beno or anyone else, how do these lock nuts work? Do you just hand thread them on the stud until they stop, and then ratchet them and the stud down on the O2 bracket?
 
Rookie2 said:
Hey Beno or anyone else, how do these lock nuts work? Do you just hand thread them on the stud until they stop, and then ratchet them and the stud down on the O2 bracket?
Click to expand...
Revised question.., am I correct in assuming you would not want to use these lock nuts on the existing studs? If not, is there a factory part number for new nuts, or a suitable replacement?
 
Personally, it's not worth my time to dink with them. Cut out that section of exhaust, weld in new, and weld in a new pad and studs.

I believe I paid a whopping $90 to have my exhaust guy do it for me; could've done it myself if I hadn't injured my back.

Also, a 15/32nd six point socket fits a heck of a lot better than a 12mm on these.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom