Strategies for rusted oxygen sensors, bolts, and nuts? (1 Viewer)

[vankho]

This was on my to do list, but got prioritized higher since I recently got a Code 28. Figured I just replace both O2 sensors.

I have my Denso parts ready, and crawl under my FJ62 and see this beauty (attached below). One sensor doesn't even have nuts that have essentially corroded away, the other has some semblance of a bolt but it isn't looking to great either. I took it to a local mechanic to see if it was something they could tackle since I don’t have the tools for this. They didn't want to touch it! They recommended fabricating a whole new set of header pipes with sensor bungs at an exhaust shop, which solves it, but would like that to be the last resort.

Does anyone know how the bolts are attached to the bung? Are they welded on or are they double-ended threaded bolts in holes in the pipe? My assumption (and hope) is that I can just start getting through the rust, apply some penetrating oil, extract the bolts, and force the sensor off.

Thoughts? Pictures or advice appreciated!

 

[YooperCruiser]

This was on my to do list, but got prioritized higher since I recently got a Code 28. Figured I just replace both O2 sensors.

I have my Denso parts ready, and crawl under my FJ62 and see this beauty (attached below). One sensor doesn't even have nuts that have essentially corroded away, the other has some semblance of a bolt but it isn't looking to great either. I took it to a local mechanic to see if it was something they could tackle since I don’t have the tools for this. They didn't want to touch it! They recommended fabricating a whole new set of header pipes with sensor bungs at an exhaust shop, which solves it, but would like that to be the last resort.

Does anyone know how the bolts are attached to the bung? Are they welded on or are they double-ended threaded bolts in holes in the pipe? My assumption (and hope) is that I can just start getting through the rust, apply some penetrating oil, extract the bolts, and force the sensor off.

Thoughts? Pictures or advice appreciated!

View attachment 2692928
View attachment 2692929

The bolts are studs that screw into the bung, you may be able to heat around them at the bung and vice grip them out, or if you can get what's left of those nuts off(heat will be necessary) you may be able to chase the threads with a die and be ok. Worst case you can buy new bungs on Amazon, have them welded in and weld the old ones shut.

 

[rhah]

More work to save those than what’s its worth

buy new bungs and a foot of pipe.

just cut out the bad section (where the o2 sensors are) and weld in a new 6 inch piece of pipe with new fresh bungs. Should take a whole hour if your having beers with it

 

[xtremeVA]

I've seen worse so taking those off is doable. Wire brush the parts, soak with PB Blaster, repeat this a few times.

When you go to take the nut off, use a 6 point socket for the best grip. Use an impact driver on the socket if you have room for that tool.

You can always go with the welding technique discussed above if everything gets foo-bared.

Good luck.

 

[Seth S]

O2 sensors you often have to heat the area around it with a torch and get it nice and red before trying to loosen the O2.

 

[Oneops]

Slee has some really nice contoured
bungs. A bit pricey but they include studs and lock nuts. Looks like you might be in new bung and possibly a section of pipe territory.