Replacing o2 sensor fail

Got an engine code saying to replace b1s1 o2 sensor. Picked it up, got under the truck and after a lot of awkward positioning to get to it, I finally got the first nut off. Second one wasn't as easy. Eventually got it coming off, then it became hard to turn again. Put a light on it since it was getting dark, and realize the entire bolt was facing a completely different direction then the first one. Can't get the damn thing off.

So what exactly are my options here? Do I have to just grind it off? How would I go about fixing it?

 

Picture?

 

Didn't think to take one. I'll try to remember to after work tomorrow

 

Make sure you put some kind of penetrating fluid on it and let it set for a bit. You do not want to snap that stud off. It will make a 15min job a several hour job.

 

For me the easy way is to remove the pipe cut off the old bung weld on a new one install new studs put it back together.

Here in the great brine belt I tried drilling out the broken rusted studs it was a pain.

By far faster for me just to replace the bung with a new one as cheap as they are.

 

Here's a pic for you guys

 

As of now I don't have a welder or otherwise that would have been my first choice. What exactly is the bung I haven't heard that before

 

it looks cross threaded, I used a mini 1/4 inch drive ratchet and a deep socket to remove mine ,when I used a standard box/open end wrench it didn't give me the bite on that nut that the socket did. and I also untightened and then retightened the nut with penetrating oil to help clean the threads as I was doing it.

 

Bung is the flanged fitting on the exhaust pipe.

That doesn't look good. Looks like the stud is bent or cracked already...

 

See the raised part that is welded to the pipe that the sensor bolts to. Thats the weld bung, spray some PB blaster on the nuts and see if it will break loose.

 

stud is toast already, one more turn and it will break the rest of the way, you have a couple of options....first, finish removing the bad nut/broken stud and then the good nut. If you are in a rush and/or do not have the means to replace the stud, you can install the new O2 sensor with the good nut and stud, then with a HUGE radiator clamp you can clamp the other side down until you can get a new stud welded on...the really bad part of all this is the O2 sensor needs to be airtight, if not, it will not work properly...

really, the best solution is to get a new stud welded on pronto....the stud is 8mmx1.25 pitch, that keeps everything is matched up thread wise...

next time soak the krap out of them with PB blaster for a couple of days, it helps...

Good luck with the fix....old exhaust shiza purely sucks.....

 

That's what I thought happened at first until I looked at it more carefully. It's bent

So I should just go ahead and grind it off you think? And yeah I realize I should have done that. I replaced my downstream one before and didn't need any that's why I didnt think I needed to use anything to get these off. The problem is like you said an old exhaust and an awkward angle.

 

That's what I thought happened at first until I looked at it more carefully. It's bent

So I should just go ahead and grind it off you think? And yeah I realize I should have done that. I replaced my downstream one before and didn't need any that's why I didnt think I needed to use anything to get these off. The problem is like you said an old exhaust and an awkward angle.

 

if your going to cut it off try to retighten the bolt down spray with wd 40 and then untighten, up and down, maybe you can eventually get it off the stud and then bend then stud straight after you got it off,patience, the last resort is cutting it off. I had to use a tiny mini ratchet with a deep socket you wont get a good bite on that nut with a box end wrench. this is how I removed my nuts on my o2 sensor

 

also if you do cut it off ive seen where a dude used a stainless radiator hose clamp after he had to cut off both studs could be a temp fix for awhiles

 

Again, the stud is toast, it is already started to fracture....the studs in question are harder than hell, the only way it could get bent like that is with a BF hammer, or over torqueage from trying to remove....ask me how I know this....depending on where you live combined with age of truck, exhaust nuts and bolts are a biatch at best to remove....the rear O2 nuts on mine had degraded to basically nothing, they came off only because there was nothing left, the front sensor (which is what I think the pic is showing) was a piece of cake, up and out of the way of salt and grime....

You do have a bit of a task to fix....but it is fixable, just make sure the base where it is welded gets ground down so the leftover welding chunks don't interfere with the new O2's FLUSH attachment....

 

if you cant remove the nut I recommend going to a muffler shop and pay the $$$ to get it fixed,having the check engine light on isn't going to fuck the truck up till you get it there. don't cut off anything till you have a plan B on how to secure the new sensor after removing it.

 

if its bent try taking a BF Hammer and bang it straight you aint got nothing to lose by trying then maybeyou cant unbolt it

 

a little ratchet like this with a deep 10mm socket, you can get in there better with better leverage and bite

 

LOL, one hit with a BFH will snap what is left of the stud....I have been there before....when a stud like this gets bent like that from attempted removal, the STUD has failed.....

Can't hurt to try, no matter the result, welding a new stud on is in your future....

Btw, that wrench is WAY too small to solve this problem, at least with removal...it would work with reinstall on new stud with new nuts though....

Again, exhaust stuff is a biatch to work with....old and rusted, frozen solid....heat and channel locks sometimes work if threads are stripped to remove messed up stud, but when the stud is fractured, nothing short of replacement will suffice...drilling out is near impossible without complete removal of the precat, even then, it would be a biatch....that opens up a whole new can o worms, the three nuts and studs on the upper exhaust flange are a PITA....